Mehul Parikh: look at sustainability or more sustainable buildings then durability is the key. the product is not really the reason behind most failures. people have actually used jaggery solution mixed with cement on the roof.
Steven Pacitti: Hello and welcome to Polycast by UT. Today we are looking at waterproofing beyond the membrane where polyurethane fits in the next generation of building envelopes. Why do waterproofing systems fail? When is polyurethane the right choice and when is it not? And how should keeping a building dry connect with keeping it comfortable? energy efficient and fit for a long working life. Well, my guest today is Mehul Parikh, a civil engineer and waterproofing specialist with more than three decades of experience in building envelope protection. He helped grow Neena into India's largest specialist waterproofing contractor, continuing as MD of Neena Percept until 2024 and then later held a senior technical role at Pidilite. Today, he advises Pidalite and runs Enverdure, an independent consultancy focused on high performance, durable and sustainable waterproofing solutions. Mayho, welcome to the show.
Mehul Parikh: Thank you, Stephen. It's wonderful to be here and I look forward to a rollicking conversation.
Steven Pacitti: Yeah Thank you. Well, Mehul, I want to begin by presenting you with an imaginary building. So let's say we've got a brand new apartment block in India. We've specified
Mehul Parikh: Mm-hmm.
Steven Pacitti: some good concrete, good insulation, good windows. We've calculated its energy performance. Everyone's delighted with it. But then the monsoon arrives.
Mehul Parikh: Mm-hmm. Mm-hmm. Mm-hmm.
Steven Pacitti: water gets into a badly detailed joint, there's a bit of seepage, the insulation gets wet, we get some damp, maybe
Mehul Parikh: Thank
Steven Pacitti: some corrosion and suddenly the building that we've designed isn't the building that we've got. Now India seems to have a challenge in this area. I saw a study this year that inspected I think 110 homes across 24 new Indian residential buildings and they found 105 different categories of defects, which if you combined with parts of India where there are extraordinary combinations of rain and humidity, we potentially
Mehul Parikh: Mm-hmm.
Steven Pacitti: could find ourselves with problems. So what that
Mehul Parikh: Mm-hmm.
Steven Pacitti: study kind of suggests is that there can be a gap between how a building is designed and how it's delivered. So I wanted to ask you to start off, Mayhil, in your experience, where does that gap most often occur? So is that design, materials, workmanship, and is India getting better at closing that gap?
Mehul Parikh: Actually it's a very important question, Stephen, and thank you for starting off with that. So, you know, where I've seen in my experience over so many years, and this is actually what I'm trying to solve, okay, in the current consulting that I'm going ahead with. In India, is sadly a fear, which I honestly trying to see if I can address that. A fear when people buy an apartment house, very rarely would you have people wanting to buy a top floor apartment. And one of the risks or one of the fears that people face is water leakage. So a top floor apartment, you might sort of think that it would be a premium apartment. because it might probably have the best view and things like that you
Steven Pacitti: house yeah
Mehul Parikh: know and you're possibly away from the din of the city at lower floors and everything but there is this kind of latent fear in the mind of the common man a buyer of an apartment that is it going to leak and how safe I am from from the monsoon you know in that aspect
Steven Pacitti: Yeah.
Mehul Parikh: so while obviously I was managing our business in Nina on the water-boofing side we actually did a kind of of of work in terms of experience and things that might have worked well, that could have been better and things like that.
Steven Pacitti: Hmm.
Mehul Parikh: So we did an analysis of about 150 projects that were executed through different times, different types of projects. potential commercial hotels, different types of structures, some were built differently, all of that. And what that analysis kind of threw back at us was that, you know, there are typically five reasons why you can have water leakages. That is what my sense is based on that experience. You can actually have water leakage because of a simple thing that you've missed out areas of a structure that should have been waterproofed. You've just not waterproofed some potential risk areas where the rain could have impacted or it could be internal areas also not necessarily just monsoon driven leakages but things
Steven Pacitti: Yes.
Mehul Parikh: within the structure that should have been waterproofed wet areas and things like that but they haven't been so they were missed out and then that's
Steven Pacitti: Right. Right.
Mehul Parikh: an obvious reason for water to come in. You then have the next reason which is wrong system selection you didn't select the right product for the right surface or the right situation sometimes
Steven Pacitti: show.
Mehul Parikh: specifications are also deficient they are not correct correctly worded, they are insufficiently drafted, not clear, could be a mix of things that have been picked up from here and there, a kind of copy paste approach sometimes.
Steven Pacitti: Mm.
Mehul Parikh: So the specification or the system selection could be the next set of problem, know. You then have application errors, obviously, is, you know, a major because that's where the human element comes in terms of things not done correctly on site, untrained people working and gaps
Steven Pacitti: Yep.
Mehul Parikh: in terms of how the method statement should have been implemented but wasn't implemented. You then have another very important set of cause of failure which is damage to the water-buffing either during its installation by other trades
Steven Pacitti: Right.
Mehul Parikh: or also post installation you know once it's handed over and it's put into service that's when water-buffing can get damaged frequently and that's again because of incorrect or know missed out planning detail in terms of how the sequence of execution on site is going to flow which trade
Steven Pacitti: Right.
Mehul Parikh: does what first or when do they come back and do the next step things like that whether
Steven Pacitti: Yeah.
Mehul Parikh: water moving gets protected by whom you know or does it just let you get left exposed for a long period of time before the next activity happens so then that's the risk again and then
Steven Pacitti: Yeah.
Mehul Parikh: finally you have poor product quality so these five
Steven Pacitti: you
Mehul Parikh: things generally have been you know i think reasons why failures can happen now sadly
Steven Pacitti: Hmm.
Mehul Parikh: what also happens is when When there is a leakage, people start with the question that I used X product and it hasn't worked out. Whereas actually the product is not really the reason behind most failures. It's actually a very small percentage and that 150 odd project that we had looked at, we found that only about 8 % if I remember the number correctly is where
Steven Pacitti: Yeah.
Mehul Parikh: actually there could have been a product related issue. The rest of it, more than 90 % was So almost about 40 % was because of wrong system selection or an incorrect
Steven Pacitti: Yeah.
Mehul Parikh: specification that was a very big chunk and then obviously a major part about 55 % I think was because of application errors, damages on site, things which actually happened on the ground. So those reasons tell me that when I actually see a failure, the approach
Steven Pacitti: Hmm.
Mehul Parikh: to analyzing failure comes from firstly accepting that Water proofing is a science. It's not just a trade. It's not a product that we're just buying.
Steven Pacitti: Yeah
Mehul Parikh: You have to deal with it probably like a science. And that's where the analysis then can be done better because you have to kind of trace the path of water literally in terms of the whole journey of water proofing. How did that happen? You know, and where could it have gone wrong? Whether
Steven Pacitti: Hmm.
Mehul Parikh: it, you know, all those five reasons, you have to kind of analyze them through and see whether, you know, which part of the process during that construction. stage did someone go wrong that's where you actually then find out where the problem lies but yes the leakages do occur because of all these multiple factors.
Steven Pacitti: Yeah, it makes me think about the, I know it's slightly unrelated, but it makes me think of the memorial pool in Washington and the hoo-ha about that. And
Mehul Parikh: Mm-hmm. Yeah.
Steven Pacitti: a lot of initial blame was laid at the materials and all of this, but actually it was because they were rushed to do the job. And
Mehul Parikh: Yep.
Steven Pacitti: I wonder as well whether the construction contractors, the materials, suppliers, specifiers are under so much pressure to get things done in such a short timeframe sometimes that they do things too quickly, they miss things, they rush processes that perhaps need to be slower. With polyurethane waterproofing membranes they often need to cure for a period of time before obviously you apply a coating. So if you rush that
Mehul Parikh: Yes or yes? Absolutely.
Steven Pacitti: process then you undermine it.
Mehul Parikh: yes, absolutely and that's where the point about wrong system selection or an incorrect specification comes. So let's say for example you are going to construct an underground metro station roof and you have to waterproof it and you go around specifying a cold applied polyurethane membrane which will have decent mechanical properties like tensile strength and elongation. and maybe reasonable amounts of puncture resistance. But the sequence on the ground demands that after you do water proofing, you want to put on a protection screen and bring back all the excavated material, fill it up within 24 hours and bring that area back to service. Because let's say part of that metro station roof is in an arterial road and you are kind of disrupting that road while you are constructing that metro. you want to get it back to service and open up that road to traffic and all of that fast. Now when you're designing that you need to have the ability to foresee that the water roofing cannot be something that requires a seven day cure because then it defeats the purpose of being able to get the construction done quickly and that's where things may go wrong because you've done a water roofing that takes seven days to cure but you've gone back and backfilled it on the second or third day. Now the water roofing is not designed for that. It's going
Steven Pacitti: Yeah.
Mehul Parikh: to you know have that risk of failure. So those kind of you know performance based evaluation in terms of how what are you constructing
Steven Pacitti: Hmm.
Mehul Parikh: and how are you going to be able to construct it the whole sequence many times that is missed out and we just pick up products because we might have used
Steven Pacitti: Yeah.
Mehul Parikh: them somewhere in some other project we bring some reference of that and try and fit it onto the next project without seeing the fitment. So fit for purpose is
Steven Pacitti: Right.
Mehul Parikh: what is needed which often is missed out.
Steven Pacitti: Is there also a misunderstanding or, you know, not necessarily just in India, but is waterproofing in the construction sector still thought of as something you apply to stop a roof leaking? But really we should be thinking about it in terms of the whole building's climate resilience, its energy efficiency. You know, we think about waterproofing actually. is from the ground up, it's from day dot and from day one of a construction, it's the basement, it's the foundations all the way to the roof. Is there a misunderstanding there or is or are things improving in terms of how waterproofing is viewed in the construction sector?
Mehul Parikh: So see, yes, there is obviously improvement. Things are changing. There is more awareness that is coming in partly also because of regulation. is regulatory
Steven Pacitti: Okay.
Mehul Parikh: pressure on real estate developers in India, for example. We have a new law that came into being a few years back called the RERA, the Real Estate Regulation Act, the RERA as it is commonly called in India. So RERA
Steven Pacitti: Okay. Right.
Mehul Parikh: generally mandates a five the
Steven Pacitti: I see. Yeah.
Mehul Parikh: this cut copy paste approach you know and and the holistic approach in terms of looking at water proofing right from the design stage that is still missing you know a
Steven Pacitti: Right.
Mehul Parikh: lot of people still depend on just a conversation with a product supplier you know the the sales person from a manufacturer who will come in and talk about a set of products that they have to offer and then that's where the conversation happens many times I've seen that you know you have a construction that is ready to start. You have a civil contractor already on board. The designs are obviously already finalized and then someone suddenly says, okay, now is the time to get the water-puffing guys on the ground. But that's actually too late because you've already finalized your drawings, your designs, your construction process, everything is done and you're now trying to fit water-puffing into a kind of fixed geometry because you've already got the structure design in place. You already decided timelines in terms of what activity is going to happen at what stages. So many things have already been decided. Penetrations, where they are going to come in. And you are now trying to fit waterproofing around all of that. So you
Steven Pacitti: Yeah.
Mehul Parikh: are now looking at chemistry to solve a geometry or a planning problem. That's not going to work. So that is
Steven Pacitti: That's not the way to do it, yeah.
Mehul Parikh: changing. People are improving. People are looking at waterproofing a little bit more differently. And I think that's where I believe I can add impact because of the experience of doing all of this for decades. So you learn along the way. You make your mistakes. You
Steven Pacitti: Yeah.
Mehul Parikh: see other people making mistakes. And you kind of want to see if you can avoid that for the projects that are coming up. And that's what I hope.
Steven Pacitti: I think I've heard you refer to waterproofing as a fragmented industry. I wondered if you could just explain a little bit more about that and why it remains fragmented and what's likely to change.
Mehul Parikh: So it's fragmented because it's not just you know the manufacturers, water-proofing manufacturers yes we have a good set of water-proofing manufacturers that are there in India. It's fragmented because of the fact that there is no you know let's say there is no there's no defined approach towards deciding the water-proofing.
Steven Pacitti: Yeah.
Mehul Parikh: It's not brought in at a design stage. It's this very stop-start,
Steven Pacitti: Okay.
Mehul Parikh: very ad hoc basis approach that is what I was just talking about. So
Steven Pacitti: Yes.
Mehul Parikh: the lack of a professional approach like so many specialist items in a construction project go through a design like you have facade you don't just buy aluminium panels and stick them on the wall you will go through a design process for your facade for so many other things and that has been lacking so that is one thing the other thing is know a lot of the installation that happens happens through very small outfits small applicators and there is no defined system to train them to certify them. Now there are some companies like yes you know because I was part of Pidlite closely for so long and I still advise so I know that there are some professional companies like Pidlite maybe there are few others as well who are taking the effort to train applicators to certify them according
Steven Pacitti: Okay.
Mehul Parikh: to their skill sets according to their capability in terms of what kind of people do they have what kind of technologies they can apply. it's not necessary that an applicator who can apply a cementitious coating for example, whether they can also apply
Steven Pacitti: Hmm.
Mehul Parikh: a polyurethane membrane, whether they can also do a spray applied polyurethane foam insulation, those capabilities
Steven Pacitti: Yeah.
Mehul Parikh: will be different. The skill sets, the kind of supervision control, equipment that you will need, all of this is not so well available in terms of a database that you can pick.
Steven Pacitti: right.
Mehul Parikh: and you can select the application partner that you want to bring in to execute. So all that is not currently there in India so easily available for people to rely on.
Steven Pacitti: Do we need legislation, do you think, to say actually you've got to use a certified applicator? You've got to get someone who knows what they're talking about into the projects.
Mehul Parikh: So yes, there are some steps coming up, think, like for example, we have this new National Building Code, NBC 2026 that has just been published. So there are steps going
Steven Pacitti: Yes.
Mehul Parikh: forward in that direction. And there are organizations like you have the Construction Industry Development Council, CIDC. I have also been working closely with them on some water-boofing codes that they want to actually draft. And they've got a
Steven Pacitti: Okay.
Mehul Parikh: group of industry experts I am part of that group which has been working on drafting standards or codes for waterproofing applicable to India. there are steps like this that are happening and CIDC for example does certify technicians, you the actual application guys who are installing the product on the site not just the companies by themselves
Steven Pacitti: I understand. Yep.
Mehul Parikh: but the actual installers so they are certifying them in terms of their capability to install.
Steven Pacitti: right.
Mehul Parikh: There are steps that are happening, but I mean if we can do it faster then because the industry is so big, you you've got thousands of projects happening everywhere. So the pace at which
Steven Pacitti: course, yeah.
Mehul Parikh: all of this is happening and what is needed on the ground that gap needs to be kind of bridged a little sooner.
Steven Pacitti: I mean, I was in Mumbai recently and I've seen the scale of the development that is going to, is and is going to take place there. So there's huge amounts of projects, lot of pressure on getting things done quickly. It brings us nicely onto material choice, Mehul. now people often associate, of course, polyurethane with insulation foam. Could you
Mehul Parikh: Okay.
Steven Pacitti: explain its roles specifically in keeping buildings dry as a sort of a sealant, a membrane? And where does polyurethane have advantages over alternative materials?
Mehul Parikh: Yeah sure, so when you talk about water-cuffing, you will always have a choice, right? Whether you want to use polyurethane, whether you want to use a cementitious coating, acrylics, you have MMA and you have so many other, you know, polymer types and they come in different forms. You could use a liquid applied coating or a sheet membrane, PVC or TPO. mean, so the options are there. I think when you talk about water-cuffing, it all comes comes down to the design in terms of how, what is the performance expectation that you are expecting to be delivered, what is the kind of construction that is happening, what kind of geography it is being built in, what are the kind of climate impact that it is going to be expected to sustain, those kind of things need to be asked. Then the time in which is, what is the timeline? We spoke about the metro project, where you saying that you you want to build something and put backfill on quickly so what kind of time are you going to allow on the site for construction what kind of interfaces does the water roofing have to deal with different rates so all of those things need to be analyzed which is why you need a water roofing specialist because a product supplier on their own or a water roofing you know applicator or the civil contractor these are the guys who are not going
Steven Pacitti: and
Mehul Parikh: to be able to deal with those questions
Steven Pacitti: Yeah.
Mehul Parikh: you might have a basement for example with pile foundation. So you will need to do a detailing where the pile caps and the raft slab are going to interface. So all of this requires thought in terms of what product and what solution is going to fit well. The beauty with polyurethane and that's why I think many of us use it increasingly is because it's versatile. So you can use
Steven Pacitti: Yes.
Mehul Parikh: it in the form of a coating and then again you have coatings which can be one component or you can have two component coating which have reactive chemistry which take it to a higher level of performance you then have hybrids with polyurea and polyurethane which can be instant setting with even higher mechanical performance and spray applied so you can deal with large areas at a time very quickly so you have all those you know
Steven Pacitti: Yeah.
Mehul Parikh: capabilities with polyurethane you have grouts that can help you to deal with remedial water proofing should you have a leak and you want to block it you can inject polyurethane in different forms and deal with that and then of course you have your insulation with spray applied
Steven Pacitti: Hmm.
Mehul Parikh: polyurethane foam that can that sits very well on on roofs so the beauty with polyurethane is that you have all these different ways in which it can be
Steven Pacitti: Yeah.
Mehul Parikh: brought to site it can be installed on site and give you solutions and and the chemistry is also evolving so you now have not just from the formulation side but from an application point you have polyurethane which can be applied on slightly damp surfaces you have you know formulations those are
Steven Pacitti: Okay, yes.
Mehul Parikh: great because they are dealing with the kind of problems that you know India typically has you know we have high humidity in many places we have our
Steven Pacitti: Yeah.
Mehul Parikh: monsoon to deal with so those kind of conditions also we have the ability to formulate and create products so there are solutions and I think polyurethane being that
Steven Pacitti: Yeah.
Mehul Parikh: versatile product is helping to solve many of those practical issues.
Steven Pacitti: So you're obviously as a consultant, are, I would assume, sort of materials agnostic to waterproofing. You do have obviously a long history with polyurethane. And you mentioned there that polyurethane is being favored. So is there a concerted transition? other materials over to polyurethane in these waterproofing applications? Is there a big big shift?
Mehul Parikh: So I think it's because of the versatility and the kind of performance features that we are seeing. India traditionally for example, the roofs, we have been using a system, I would not call it a product, a system or a technique which is called brick-backed coba where you simply are laying brick pieces on a cement mortar bedding. Essentially you are creating a sloped surface because they are laid to a gradient and you you finish that layer on the top with another layer of cement mortar. What you are essentially trying to do is creating a surface that has know a quick runoff capability so that you water that's falling is taken to the drain points as quickly as possible and that's the general you know philosophy behind that. And then of course the brick being the kind of a little bit absorbent material should there be some you know penetration which there will be through that mortar layer it will kind of retain some of that moisture for a little longer time without allowing it to straight away go down to the slab plus
Steven Pacitti: Yes.
Mehul Parikh: the brick has a bit of a know it's a better insulation properties if you may call it that compared to you know just leaving the slab open so those
Steven Pacitti: Yeah.
Mehul Parikh: kind of things have been traditionally there and polyurethane is now the obvious solution one of the reasons is over time construction projects have become bigger roofs have become larger earlier you might have a 5000 square feet roof which was considered a decent size today you have large commercial roofs you have data centers and so many different types of the construction has evolved
Steven Pacitti: Yeah.
Mehul Parikh: and with those large roofs you have IT buildings you know information technology centers and all of that they have typically 30-40 thousand square feet roofs 3000-4000 square meters now those roofs are going to move or going to experience movements
Steven Pacitti: Yeah.
Mehul Parikh: because of the climate what it is going to throw at you. So you
Steven Pacitti: Yeah.
Mehul Parikh: are going to see daytime temperature changes and all of that translating into the need for a far more flexible system, far more resilient system on the roof. And
Steven Pacitti: Yeah.
Mehul Parikh: Brick-Bad-Coba or some of the traditional methods have been rigid. have not been able to, they can't deal with the
Steven Pacitti: Yeah.
Mehul Parikh: flexibility requirements. Polyurethane inherently is flexible, the liquid applied. membranes will have far better tensile properties and elongation and all of that to deal with the movements expected. So
Steven Pacitti: Yeah.
Mehul Parikh: that creates a reason for acceptance you know because people realize
Steven Pacitti: Yeah.
Mehul Parikh: that the older techniques are obsolete now there is time to move
Steven Pacitti: Yeah.
Mehul Parikh: on and the first progression from that very old Brigbad Koba method was to use cementitious coatings as an underlayment. So you would still have Brigbad Koba sitting on top
Steven Pacitti: Yeah.
Mehul Parikh: but you would have a cementitious coating a polymer modified cementitious
Steven Pacitti: Hmm.
Mehul Parikh: coating as the kind of water-boofing system below that. Now,
Steven Pacitti: Yeah.
Mehul Parikh: while it was a step forward, cementitious coatings again will have very limited flexibility. So the next step was then people started looking at acrylics. But acrylics are not as resilient to long-term water exposure as a polyurethane liquid membrane will be. So
Steven Pacitti: Right.
Mehul Parikh: when you look at those kind of performance expectations, ability to resist hydrolysis for example or dynamic crack bridging, effects of long
Steven Pacitti: Hmm.
Mehul Parikh: term water bonding. All of that polyurethane generally tends to provide you formulation that can perform in those demanding environments and that's how I think over time the acceptance
Steven Pacitti: Yeah.
Mehul Parikh: towards polyurethane has been improving.
Steven Pacitti: And it's interesting, isn't it? Because I we see, I mean, in the UK, we've had issues with spray foam in loft spaces. We've had
Mehul Parikh: Mm-hmm.
Steven Pacitti: this push to have insulation into your cavities of houses to improve energy efficiency. But there's a lack of maybe understanding at government level sometimes in terms of the material science and the fact that actually what you're doing by creating something that is so sealed is that you're not allowing airflow, It has to be breathable. Otherwise you're going to get all sorts of damp and mould problems. And I think maybe it's getting that material science education to those kind of levels. And maybe the associations, are part of that education to enable the building standards to improve overall, would you say?
Mehul Parikh: Yes, that's true. That's true. So mean organizations like CIDC or Indian Concrete Institute, there are so many such industry bodies and
Steven Pacitti: Yeah.
Mehul Parikh: there's a lot of, so you have for example Waterproofers Association of India and they just had a seminar
Steven Pacitti: Okay.
Mehul Parikh: a couple of months back. So there is a lot of, you know, technical knowledge being shared more widely now. So that is helping the, you know, acceptance of good specifications, good techniques. People are understanding that, you know, it requires a professional approach not just you know a cut copy paste approach that that kind
Steven Pacitti: Yep.
Mehul Parikh: of awareness is slowly coming in and for example you have the Indian standard IS 16471 which is meant for substructure water roofing but that's where construction typically will start and you also
Steven Pacitti: Okay.
Mehul Parikh: have then the British standard BS 8102 now standards
Steven Pacitti: right.
Mehul Parikh: like these for example clearly recommend that you need to have a specialist, a water-boofing specialist as part of the design team.
Steven Pacitti: Yep.
Mehul Parikh: And even this new national building code, NBC 2026, it also talks about the fact that you need subject matter experts as part of a design team in a project right from the early stage, right from
Steven Pacitti: Understood. Yeah. Yeah.
Mehul Parikh: the design concept stage. And that's where, you know, acceptance is coming in, you know, that yes, we need to think of water-boofing not just as a product that you just simply you know bring to the site and get someone to just apply for but think about it in terms of how it will
Steven Pacitti: Yeah.
Mehul Parikh: fit a particular project. So
Steven Pacitti: Yeah.
Mehul Parikh: it's early days I would say the some of the institutional developers you know the larger structural consultants the more evolved architects all of these and project management companies these are all slowly realizing the need for this specialist approach you know and yes
Steven Pacitti: Yeah.
Mehul Parikh: so you know it that's the way think a market will move you will have some of the you know aware people taking that step forward and then a larger market will follow that yes this seems to be the obvious right path towards designing things on a fit for purpose project specific basis
Steven Pacitti: You touched upon some of the changes behind the scenes I was looking at, the Energy Conservation Sustainable Building Code, the Residential Eco-Newas Samhita. I've probably butchered the way of saying that, the Energy Efficiency Code for India, for residential buildings. They provide
Mehul Parikh: Yeah. Yeah.
Steven Pacitti: an important backdrop to that. Are energy performance requirements changing how if we focus on roofs, how they're specified so we're bringing insulation and waterproofing together or are they still largely designed and purchased as separate packages? Is there more
Mehul Parikh: Yeah.
Steven Pacitti: of an integration of those systems?
Mehul Parikh: No, so that's I mean that's true in both ways. First is that yes, we have now, you know, these building codes, for example, or the regulatory documents like you have the ECSBC, the Energy Conservation and Sustainability Building Code that was published in 2024 ECSBC 2024. And that clearly, so that's focused on commercial buildings. Firstly, it's not something that is applicable to every construction project but it's applicable to commercial buildings largely above a certain energy consumption criteria that it defines but the good thing is that it is applicable to all those commercial buildings which are larger than that threshold value. So most buildings do get covered, the ones that are typically built to house large offices or institutional buildings for a corporate office or a shopping mall or a hotel for example. a hospital, an educational college, government office, all of those kind of buildings by default will get covered through that ECSBC 2024 criteria. And the good part is that it's talking about the fact that it's not just that insulation should be there. It's very clearly talking about it. If I remember, it's the clause, I think it's in chapter 5, 5.3.1, if I remember it correctly, that's the clause that talks about insulation having to be an over deck insulation applied on the top of the roof not an under deck insulation. That's another
Steven Pacitti: I see. Right.
Mehul Parikh: change because in India historically a lot of buildings have been insulated particularly the air conditioned buildings because there was an obvious need to do it you know from a HVAC point of view for example but they used to be typically under deck because that was easy you know just take insulation from below and you thought that you're getting a good insulation but slowly people are realizing that like you block water from the source you have to obviously also block heat from the source and if it's coming from the roof downwards then you're better off putting insulation on the top of that roof and kind of protecting that roof rather than allowing heat to get into a building and then
Steven Pacitti: Yeah.
Mehul Parikh: trying to you know block it from underneath so that kind of realization has come ECSBC has given that bit of push also and even before ECSBC we had of course green building so we have a lot of commercial buildings and increasingly a lot of residential buildings also because there are some incentives that come with those certifications and green buildings typically tend to have energy efficiency as one of the essential elements. So yes the
Steven Pacitti: Yeah.
Mehul Parikh: roof insulation has been kind of picking up along the way and while it's happening the first approach was to answer the second part of your question is whether it's dealt with separately. So yes from a procurement angle or a commercial angle the procurement teams would not recognize the fact that when you are putting insulation on the top of a roof it is now part of a roof assembly. It's not just another layer sitting there along with other
Steven Pacitti: Yes.
Mehul Parikh: things and it has to integrate with water roofing. So previously there have been a lot of projects which have been tendered out with insulation just as a separate line item so people would want to buy the insulation or source it. from someone who supplies insulation and then find out that you know on the ground the interface between insulation and water proofing will not be taken care of by one person if you have multiple people but those failures have happened people have done that mistake got insulation got it to the site through someone else got a water proofing guy to do their job and then suddenly realizing maybe a year or two down the line when something leaks that whom do you catch hold of and then obviously is passing the buck going to happen so Today specifications are evolving, they are getting better
Steven Pacitti: Yeah.
Mehul Parikh: and people are integrating the roof insulation and waterproofing together. So it's still I would say early days but realization
Steven Pacitti: Yeah.
Mehul Parikh: is coming in that you have to look at it as a roof system because the roof is going
Steven Pacitti: Yes.
Mehul Parikh: to take care of heat insulation, know, waterproofing, the movement that are going to happen. There are drainage outlets that need to be detailed. You increasingly have solar panels being put on a roof so they will penetration that need to be sealed around. So it's a complex
Steven Pacitti: Yep.
Mehul Parikh: you know affair and that needs to be dealt with with right expertise.
Steven Pacitti: And coatings as well, if you're coating a waterproof membrane, that is then exposed to UV, to the conditions of that particular region. are coatings of replaced when they should be generally? I guess they have a lifespan of maybe 10 to 15 years under UV. So are those things being done? because obviously that can then lead to failures if you're not maintaining.
Mehul Parikh: Yeah. So that's again a very important point. So over the years, people have not really in the past looked at maintenance or maintainability
Steven Pacitti: Hmm.
Mehul Parikh: as something that should be even thought of. People would
Steven Pacitti: Yeah.
Mehul Parikh: say that, okay, I've got this insulation done, I've got the roof completed and that's the end of it. But it has a life, and especially when you have occupied buildings, you don't want to go up and kind of rip open the entire roof. and then redo everything because in a functioning hotel for example or an office or even if it's a residential apartment you don't want to inconvenience the occupants or disrupt operations or you know sort of affect your revenue for example a hospital
Steven Pacitti: Mm.
Mehul Parikh: or a hotel you can't shut off floors simply because you want to now redo the waterproofing of the roof so
Steven Pacitti: Yeah.
Mehul Parikh: people have been now thinking about it earlier those mistakes have happened and I think that's where roof refurbishment is going to be a big let's say area area of
Steven Pacitti: Okay.
Mehul Parikh: growth it already is showing up that way because what has been constructed in the past because of what we spoke about earlier you know the lack of a very systematic approach towards the design and everything a kind of cut copy paste or older techniques which are obsolete all of that is now slowly showing through you know and another important thing is our climate is changing so no matter you know it's not just about products or it about whether we approach the construction correctly. The fundamental issue is climate is changing. So I was at a climate, I was at an event of Deloitte in October, I think 25 about a year back or so and they were launching a climate report. Okay. An India specific climate report, not some global report that had India as a footnote there, but it was actually an India specific climate report. And what I remember from that is that we are seeing almost a 1.4x increase in extreme rainfall events in India in just the last five years. And I stayed in Mumbai and there are places across India like Delhi for example, Hyderabad, all of these places which were earlier not known to have very severe monsoon risk in
Steven Pacitti: Hmm.
Mehul Parikh: that sense from the water moving point of view. But they are seeing those very very heavy intense rainfall days. So 1.4x increase in extreme rainfall. events in just five years is one observation that is there. The other pertinent observation I found was the fact that extreme heat events across India, especially in our summer months, March to say May for example, and also then later on in the year around September, October. So these extreme heat events have also gone up by I 15 fold in the last three decades. Then you also have our long period average rainfall rainfall what we call so across central India so Delhi is obviously part of that so this report also captured that and if I remember it's about 40 % more so about 1100 mm typically has now gone up to about more than 1500 close to 1600 mm of rainfall so with all of those things the climate is demanding that the water-boofing systems on the roof or elsewhere in a building which is going to you know deal with all of that have to be designed far more robustly you you can't have things that happened 30-40 years ago, continuing to deliver the solution. And that's where the maintenance element comes in. Because the climate is going to do what it is going to do, you will have to look at some levels of redundancy in the specification build up in terms of layers or solutions that you are integrating into it and also the fact that how are you going to maintain. Because you will need to go
Steven Pacitti: Yeah.
Mehul Parikh: back and reapply some sort of a top coat on a roof. that is it going to last you for the next 100 years it won't so 10 years 15 years down the line you should be able to go back and apply something on the roof that keeps it sealed nicely from you know water ingress and helps to protect the investments below in terms of whatever finishes
Steven Pacitti: Yes.
Mehul Parikh: or functionality you have so yes that's going to be the way forward
Steven Pacitti: Yes, I understand. I wanted to ask you about the Indian government's draft that they proposed in June of this year for a mandatory rating framework for new...
Mehul Parikh: Yeah, the B-E without energy efficiency.
Steven Pacitti: So that's to cover new commercial office and residential buildings of at least 20,000 square meters, I believe.
Mehul Parikh: Yeah, I remember I think that's what it says,
Steven Pacitti: Would that kind of requirement, will it change specification decisions when it comes to materials, do you think? Or will enforcement be the bigger issue here?
Mehul Parikh: See it is definitely going to change and it is going to impact and even if you go back in fact to the ECSBC, the Energy Conservation Code, even ECSBC apart from asking you to put on insulation on the top is also asking you to either put a vegetative roof on I think it's about 90 % of the exposed roof for example, exposed areas
Steven Pacitti: Okay.
Mehul Parikh: of the roof other than where have your MEP or HVAC equipment settings other than your utility areas the rest of the exposed roof should either be a vegetative roof or it should have
Steven Pacitti: Okay.
Mehul Parikh: a high SRI reflective coating on the top. Now
Steven Pacitti: I see.
Mehul Parikh: if you are possibly looking at a vegetative roof for example the water boofing requirements for a green roof a landscape roof are going to be of an elevated nature in terms of the whole performance element to it you know and
Steven Pacitti: Hmm.
Mehul Parikh: when you say high SRI coatings yes you have acrylics that do the job but when you have foot traffic ability that you are dealing with along with you know along with the fact that you want a good you know SRI value to it hybrid coatings which polyurethane blended with other polymers you know those hybrid solutions actually are going to be better you know doing that
Steven Pacitti: Yeah.
Mehul Parikh: So yes, some of the codal requirements or standards
Steven Pacitti: Yeah.
Mehul Parikh: are going to push performance expectations higher, which is good because we will end up building
Steven Pacitti: Yeah.
Mehul Parikh: better. see, when we talk about sustainability, the underlying part of all of these standards or regulations is pushing construction towards sustainability in some form. When we say
Steven Pacitti: Yeah, yeah.
Mehul Parikh: sustainability, very big word, you know, and I'm not here to define what it stands for. Each one has their own sort of view towards it. My simple thought is that durability and sustainability go hand in hand.
Steven Pacitti: Yeah.
Mehul Parikh: So if you are going to look at sustainability or wanting to have more sustainable buildings then durability is the key. You will have to have things that are going into the
Steven Pacitti: Yeah.
Mehul Parikh: whole construction process, water roofing obviously a critical part of it which are going to last for a longer period not having to repair or replace them frequently enough. and thereby conserve resources. So it's all connected in that sense,
Steven Pacitti: if we talk about a building project, when it comes to the handover stage, what objective evidence then should a building owner receive to show that the waterproofing was installed properly?
Mehul Parikh: Yeah, so I think that is very important because again going back to what I said the RERA, know, the regulation that we have in India talking about the five-year defect liability that a developer has to cater to and manage. So if you look at all of that, the traditional approach in India or maybe possibly across the world is, you get a warranty document, right? A water-proofing 10 years warranty. A warranty is obviously a commercial contract, right? It's basically saying that look, you know, if something goes wrong, that warranty will enable you to get some solution towards it. But it has to start with a proactive and a preventive sort of scientific approach that whether things have been done correctly or not. And that's where again, I think a water-proofing specialist coming on a design team is important because they will put in that framework, that whole framework in terms of not just the specification, but what is going to happen in terms of checklists that will be followed, what kind of records are going to be kept through the life cycle
Steven Pacitti: Yeah.
Mehul Parikh: of the project and be part of a handover document. So things like your batch test certificates or material test certificates that a manufacturer provides with every batch of material that comes in or even before that when you are pre-qualifying and approving products and even the water
Steven Pacitti: Yep.
Mehul Parikh: in contract, what kind of capabilities were looked at. you know, in terms of their ability to execute a particular project or the compliance of the product to the specifications or what kind of third party testing data was available on record to show that yes, this
Steven Pacitti: Yeah.
Mehul Parikh: product is going to do the job that is expected from it. And then you have all those quality checklists in terms of, you know, wet film thicknesses that are checked on the ground, surface preparation, how has it been done correctly or not, whether the detailing
Steven Pacitti: Yeah.
Mehul Parikh: around penetration has been done. And you know there are a lot of free tests that normally should I think should be done you know like wet film thickness or you know you should be testing adhesion to check whether the surface preparation is good enough to receive the coating over it or not. You can't just simply look at visually and say okay this looks fine to me let me go around applying the coating it will probably not work.
Steven Pacitti: Yeah.
Mehul Parikh: So all those data and then finally the know the flood tests or any other test that you have done to prove that the water gophing is effective. Flood tests generally
Steven Pacitti: Yeah.
Mehul Parikh: are most commonly done but they may or may not be the only solution. are newer techniques available. Some projects are adopting those. So all those checklists of handover, takeover between trades sequentially, all of that data
Steven Pacitti: Yeah.
Mehul Parikh: I think should go in finally with as-built drawings. That is a missing piece. I tell you a lot of projects today are following maybe 80 % of what I just said. Okay, the bigger projects. Not all I would say but the bigger projects being done by more institutional companies you know larger EPC contractors and all will have about 70-80 % of these items being done but the single biggest piece that I think is grossly missing across a vast majority is as-built water-puffing drawings. So you will have very rudimentary schematic drawings that get you know that get submitted at the initial stage by the know water-puffing contractor or sometime by the manufacturer, but they are not representative of the actual site. They are just very typical schematic things, know, outlining how the water moving is likely to happen. But eventually what has happened on the ground, right, which is project specific, how the details have been actually worked around, all that should come in the form of as-built drawings, which are not there. So you ultimately don't know whether water moving has been done in all the areas prone to risk, which was the first thing that I said that we don't analyze. risk sometimes we miss out areas you know we don't waterproof areas
Steven Pacitti: Yeah.
Mehul Parikh: which should be waterproofed so that whole risk assessment whether it was done correctly and eventually it has to show in terms of on the ground what was executed so all
Steven Pacitti: Yeah.
Mehul Parikh: this has to be there that's when I think a project owner or the people that the project owner hands over the documentation to you know your main your facilities managers basically all of those guys
Steven Pacitti: Yes.
Mehul Parikh: will know what was done and that be easier to do a kind of analysis is if things were to fail you will be able to trace that path backwards you know in terms of that whole journey of water proofing
Steven Pacitti: Yeah.
Mehul Parikh: right from the system selection to the execution you will probably have a better chance of finding out where things might have gone wrong and hence rectify things more easily.
Steven Pacitti: I wanted to just touch on raw materials I talking about this recently in Mumbai at our show, about the role of localization and India's domestic feedstock abilities and capacities. How exposed is Indian polyurethane waterproofing to imported feedstocks and additives? Is there an area where localisation is actually making a meaningful difference?
Mehul Parikh: So look, mean the honest answer is yes India, you know, we don't have any meaningful domestic MDI production, for example, right? And we are dependent on imports for a lot of the core raw materials, whether it's MDI, TDI, whether it's, you know, specialized polyols, We are import dependent on that sense and the vulnerability is there Sometimes it works in our favor because I think you know at times when European prices go up if China holds its price Then it's something that helps us to you know, but that's all short-term and it's not reliable in that sense so I think what has rather than the actual raw material manufacturing capability. think what India has been doing, know, and again, think, PdLite, of course, because I have been part of that, but there other companies also who have been actually developing formulating capabilities. So we are able to, yes, deal with sometimes important materials, but
Steven Pacitti: Okay. Yeah.
Mehul Parikh: getting them to, you know, getting a more meaningful formulation out of it. So it's not just relying on a product that is, let's say, honestly made for a European climate, just bringing it to India and putting it to use on a far more stringent or more aggressive climate that we will have in many places. So lot of these guys in India are actually doing some meaningful formulation efforts and coming out with products which are more suitable to being applied on Indian conditions. For example,
Steven Pacitti: Yeah.
Mehul Parikh: I can just give you this one example not intending to push a product or anything because I want to be brand agnostic but the fact is that know the Pidlite has something called Wonderproof 100. Now this product why is it exciting is because it's a primer less product. It can be applied without a primer on multiple subsets.
Steven Pacitti: Okay.
Mehul Parikh: So it's not just on concrete for example. It deals with the fact that on a roof you will have penetrations which are going to have let's say a PVC pipe for drainage or you have this know solar panel installation with a metal you know fastener or something that's going through the roof. So a product that can be applied without a primer on these multiple substrates, right, also deal with a slightly higher moisture content than
Steven Pacitti: Hmm.
Mehul Parikh: most polyurethanes will allow for and it is kind of rain proof within about an hour or two. So once you apply an hour or two later if it rains, it's not going to get washed off. plus it's UV resistant
Steven Pacitti: before I move on to a couple of sort of final lighter questions for a bit of fun, for any, polyurethane producers and, and formulators that might be listening to this podcast, what is the one, what is the one problem
Mehul Parikh: Thank
Steven Pacitti: you would most want them to solve that would make, the biggest difference on a construction site.
Mehul Parikh: See, I mean, I can have a laundry list of... things that you know coming from a practical point of view you know I am not a manufacturing let's say you know expert I have executed water roofing works so I come from that practical sense and that's where you tend to you know want the moon you know in terms of all your sort of know wish list for example but I think see if we can if we can build products you know if we can continue to formulate and build products which are capable of performing in India and I am talking about India because that's my area of work basically. So as long as you are able to have something which is genuinely tolerant of residual moisture because see that is one thing that in India you are going to be faced with. And it's not just the monsoon, the other problem is that on construction sites the developers or even the construction companies they don't give you like know 20 days or longer to wait for water buffing. They literally will cast the slab and say okay you're on it tomorrow you know so
Steven Pacitti: right.
Mehul Parikh: whether you like it or not the fact is that you have to deal with those situations so I would love to have a product that can actually do you know its job in terms of a proper cross-linking you know density that is expected
Steven Pacitti: Hmm.
Mehul Parikh: to be achieved with obviously the specified DFT and all in place but something that can be applied on a damp surface actually. without pinholes and all of that and if we can you know bring in some system that is also little intelligent you know because right now water-boofing systems are generally dumb is what I believe right you are expecting you know ways and means to check it to ensure whether it is done correctly so is there some intelligence there's so much you know we are in an AI world so I don't know maybe I'm asking for too much but is there some intelligent fabric for example of increasing the water-boofing systems are reinforced but we putting just a know a reinforcing fabric or a fleece
Steven Pacitti: Mm.
Mehul Parikh: you know to kind of enhance its mechanical properties that's what is being
Steven Pacitti: Yeah.
Mehul Parikh: done but while we are doing that can that fabric have some electrical grid in it which can sense a breach in the water-boofing system or when water comes in contact so obviously there's a breach and the system is not performing is there something
Steven Pacitti: Yeah.
Mehul Parikh: that can trigger an early warning reaction so even before you have let's let's say the manifestation of leakage in terms of water coming down, you are able to address a problem or being able to identify it. So let's say that it may not give you an early warning alert, but even if it can kind of mark out that problem and there can be a separate tool that is able to walk on the roof for example and it can kind of
Steven Pacitti: Yeah.
Mehul Parikh: connect with each other and say, okay, this is where the problem is. So some intelligent sensor which can be integrated into the system. Something like this you know. Maybe it's asking for too much but.
Steven Pacitti: If anyone's listening and has answers to Mayhul then drop me an email. Mayhul, I want
Mehul Parikh: Thank you.
Steven Pacitti: to finish with a couple of quickfire questions if I may just for a bit of fun. So I mean you've obviously seen a lot of roofs, a lot of buildings in your
Mehul Parikh: Thank
Steven Pacitti: time. What's the most inventive and perhaps least convincing attempt to stop a leak that you've ever seen?
Mehul Parikh: I will tell you funnily people have been using jaggery solution. You have
Steven Pacitti: What's that?
Mehul Parikh: jaggery sugar, jaggery.
Steven Pacitti: okay. Right, right.
Mehul Parikh: So people have actually used jaggery solution mixed with cement on the roof. as a very primitive rudimentary water roofing and you will be finally surprised that it sometimes actually stops water maybe for a short time but it actually does that you know so people have gone around applying you know that kind of thing
Steven Pacitti: I suppose yeah it's novel ideas but you know it's all science. Have you ever walked into a building, Mayhill, looked at one detail and thought, do you know what, I'll be back here after the monsoon.
Mehul Parikh: yes, it happens all the time. It happens all the time. And sometimes, you know, I've actually been called to, you know, I can't name buildings obviously or projects, but I've actually had that experience many times.
Steven Pacitti: Yeah, I've learned a lot today about waterproofing. So thank you so much for your time, Mayhill.
Mehul Parikh: Thank you. Thank you, Stephen. It was wonderful.
Steven Pacitti: You
Mehul Parikh: Thank you,
Steven Pacitti: been listening to Polycast by UT, helping your business expand in all the right places. We'll see you again soon.
Steven Pacitti: Hello and welcome to Polycast by UT. Today we are looking at waterproofing beyond the membrane where polyurethane fits in the next generation of building envelopes. Why do waterproofing systems fail? When is polyurethane the right choice and when is it not? And how should keeping a building dry connect with keeping it comfortable? energy efficient and fit for a long working life. Well, my guest today is Mehul Parikh, a civil engineer and waterproofing specialist with more than three decades of experience in building envelope protection. He helped grow Neena into India's largest specialist waterproofing contractor, continuing as MD of Neena Percept until 2024 and then later held a senior technical role at Pidilite. Today, he advises Pidalite and runs Enverdure, an independent consultancy focused on high performance, durable and sustainable waterproofing solutions. Mayho, welcome to the show.
Mehul Parikh: Thank you, Stephen. It's wonderful to be here and I look forward to a rollicking conversation.
Steven Pacitti: Yeah Thank you. Well, Mehul, I want to begin by presenting you with an imaginary building. So let's say we've got a brand new apartment block in India. We've specified
Mehul Parikh: Mm-hmm.
Steven Pacitti: some good concrete, good insulation, good windows. We've calculated its energy performance. Everyone's delighted with it. But then the monsoon arrives.
Mehul Parikh: Mm-hmm. Mm-hmm. Mm-hmm.
Steven Pacitti: water gets into a badly detailed joint, there's a bit of seepage, the insulation gets wet, we get some damp, maybe
Mehul Parikh: Thank
Steven Pacitti: some corrosion and suddenly the building that we've designed isn't the building that we've got. Now India seems to have a challenge in this area. I saw a study this year that inspected I think 110 homes across 24 new Indian residential buildings and they found 105 different categories of defects, which if you combined with parts of India where there are extraordinary combinations of rain and humidity, we potentially
Mehul Parikh: Mm-hmm.
Steven Pacitti: could find ourselves with problems. So what that
Mehul Parikh: Mm-hmm.
Steven Pacitti: study kind of suggests is that there can be a gap between how a building is designed and how it's delivered. So I wanted to ask you to start off, Mayhil, in your experience, where does that gap most often occur? So is that design, materials, workmanship, and is India getting better at closing that gap?
Mehul Parikh: Actually it's a very important question, Stephen, and thank you for starting off with that. So, you know, where I've seen in my experience over so many years, and this is actually what I'm trying to solve, okay, in the current consulting that I'm going ahead with. In India, is sadly a fear, which I honestly trying to see if I can address that. A fear when people buy an apartment house, very rarely would you have people wanting to buy a top floor apartment. And one of the risks or one of the fears that people face is water leakage. So a top floor apartment, you might sort of think that it would be a premium apartment. because it might probably have the best view and things like that you
Steven Pacitti: house yeah
Mehul Parikh: know and you're possibly away from the din of the city at lower floors and everything but there is this kind of latent fear in the mind of the common man a buyer of an apartment that is it going to leak and how safe I am from from the monsoon you know in that aspect
Steven Pacitti: Yeah.
Mehul Parikh: so while obviously I was managing our business in Nina on the water-boofing side we actually did a kind of of of work in terms of experience and things that might have worked well, that could have been better and things like that.
Steven Pacitti: Hmm.
Mehul Parikh: So we did an analysis of about 150 projects that were executed through different times, different types of projects. potential commercial hotels, different types of structures, some were built differently, all of that. And what that analysis kind of threw back at us was that, you know, there are typically five reasons why you can have water leakages. That is what my sense is based on that experience. You can actually have water leakage because of a simple thing that you've missed out areas of a structure that should have been waterproofed. You've just not waterproofed some potential risk areas where the rain could have impacted or it could be internal areas also not necessarily just monsoon driven leakages but things
Steven Pacitti: Yes.
Mehul Parikh: within the structure that should have been waterproofed wet areas and things like that but they haven't been so they were missed out and then that's
Steven Pacitti: Right. Right.
Mehul Parikh: an obvious reason for water to come in. You then have the next reason which is wrong system selection you didn't select the right product for the right surface or the right situation sometimes
Steven Pacitti: show.
Mehul Parikh: specifications are also deficient they are not correct correctly worded, they are insufficiently drafted, not clear, could be a mix of things that have been picked up from here and there, a kind of copy paste approach sometimes.
Steven Pacitti: Mm.
Mehul Parikh: So the specification or the system selection could be the next set of problem, know. You then have application errors, obviously, is, you know, a major because that's where the human element comes in terms of things not done correctly on site, untrained people working and gaps
Steven Pacitti: Yep.
Mehul Parikh: in terms of how the method statement should have been implemented but wasn't implemented. You then have another very important set of cause of failure which is damage to the water-buffing either during its installation by other trades
Steven Pacitti: Right.
Mehul Parikh: or also post installation you know once it's handed over and it's put into service that's when water-buffing can get damaged frequently and that's again because of incorrect or know missed out planning detail in terms of how the sequence of execution on site is going to flow which trade
Steven Pacitti: Right.
Mehul Parikh: does what first or when do they come back and do the next step things like that whether
Steven Pacitti: Yeah.
Mehul Parikh: water moving gets protected by whom you know or does it just let you get left exposed for a long period of time before the next activity happens so then that's the risk again and then
Steven Pacitti: Yeah.
Mehul Parikh: finally you have poor product quality so these five
Steven Pacitti: you
Mehul Parikh: things generally have been you know i think reasons why failures can happen now sadly
Steven Pacitti: Hmm.
Mehul Parikh: what also happens is when When there is a leakage, people start with the question that I used X product and it hasn't worked out. Whereas actually the product is not really the reason behind most failures. It's actually a very small percentage and that 150 odd project that we had looked at, we found that only about 8 % if I remember the number correctly is where
Steven Pacitti: Yeah.
Mehul Parikh: actually there could have been a product related issue. The rest of it, more than 90 % was So almost about 40 % was because of wrong system selection or an incorrect
Steven Pacitti: Yeah.
Mehul Parikh: specification that was a very big chunk and then obviously a major part about 55 % I think was because of application errors, damages on site, things which actually happened on the ground. So those reasons tell me that when I actually see a failure, the approach
Steven Pacitti: Hmm.
Mehul Parikh: to analyzing failure comes from firstly accepting that Water proofing is a science. It's not just a trade. It's not a product that we're just buying.
Steven Pacitti: Yeah
Mehul Parikh: You have to deal with it probably like a science. And that's where the analysis then can be done better because you have to kind of trace the path of water literally in terms of the whole journey of water proofing. How did that happen? You know, and where could it have gone wrong? Whether
Steven Pacitti: Hmm.
Mehul Parikh: it, you know, all those five reasons, you have to kind of analyze them through and see whether, you know, which part of the process during that construction. stage did someone go wrong that's where you actually then find out where the problem lies but yes the leakages do occur because of all these multiple factors.
Steven Pacitti: Yeah, it makes me think about the, I know it's slightly unrelated, but it makes me think of the memorial pool in Washington and the hoo-ha about that. And
Mehul Parikh: Mm-hmm. Yeah.
Steven Pacitti: a lot of initial blame was laid at the materials and all of this, but actually it was because they were rushed to do the job. And
Mehul Parikh: Yep.
Steven Pacitti: I wonder as well whether the construction contractors, the materials, suppliers, specifiers are under so much pressure to get things done in such a short timeframe sometimes that they do things too quickly, they miss things, they rush processes that perhaps need to be slower. With polyurethane waterproofing membranes they often need to cure for a period of time before obviously you apply a coating. So if you rush that
Mehul Parikh: Yes or yes? Absolutely.
Steven Pacitti: process then you undermine it.
Mehul Parikh: yes, absolutely and that's where the point about wrong system selection or an incorrect specification comes. So let's say for example you are going to construct an underground metro station roof and you have to waterproof it and you go around specifying a cold applied polyurethane membrane which will have decent mechanical properties like tensile strength and elongation. and maybe reasonable amounts of puncture resistance. But the sequence on the ground demands that after you do water proofing, you want to put on a protection screen and bring back all the excavated material, fill it up within 24 hours and bring that area back to service. Because let's say part of that metro station roof is in an arterial road and you are kind of disrupting that road while you are constructing that metro. you want to get it back to service and open up that road to traffic and all of that fast. Now when you're designing that you need to have the ability to foresee that the water roofing cannot be something that requires a seven day cure because then it defeats the purpose of being able to get the construction done quickly and that's where things may go wrong because you've done a water roofing that takes seven days to cure but you've gone back and backfilled it on the second or third day. Now the water roofing is not designed for that. It's going
Steven Pacitti: Yeah.
Mehul Parikh: to you know have that risk of failure. So those kind of you know performance based evaluation in terms of how what are you constructing
Steven Pacitti: Hmm.
Mehul Parikh: and how are you going to be able to construct it the whole sequence many times that is missed out and we just pick up products because we might have used
Steven Pacitti: Yeah.
Mehul Parikh: them somewhere in some other project we bring some reference of that and try and fit it onto the next project without seeing the fitment. So fit for purpose is
Steven Pacitti: Right.
Mehul Parikh: what is needed which often is missed out.
Steven Pacitti: Is there also a misunderstanding or, you know, not necessarily just in India, but is waterproofing in the construction sector still thought of as something you apply to stop a roof leaking? But really we should be thinking about it in terms of the whole building's climate resilience, its energy efficiency. You know, we think about waterproofing actually. is from the ground up, it's from day dot and from day one of a construction, it's the basement, it's the foundations all the way to the roof. Is there a misunderstanding there or is or are things improving in terms of how waterproofing is viewed in the construction sector?
Mehul Parikh: So see, yes, there is obviously improvement. Things are changing. There is more awareness that is coming in partly also because of regulation. is regulatory
Steven Pacitti: Okay.
Mehul Parikh: pressure on real estate developers in India, for example. We have a new law that came into being a few years back called the RERA, the Real Estate Regulation Act, the RERA as it is commonly called in India. So RERA
Steven Pacitti: Okay. Right.
Mehul Parikh: generally mandates a five the
Steven Pacitti: I see. Yeah.
Mehul Parikh: this cut copy paste approach you know and and the holistic approach in terms of looking at water proofing right from the design stage that is still missing you know a
Steven Pacitti: Right.
Mehul Parikh: lot of people still depend on just a conversation with a product supplier you know the the sales person from a manufacturer who will come in and talk about a set of products that they have to offer and then that's where the conversation happens many times I've seen that you know you have a construction that is ready to start. You have a civil contractor already on board. The designs are obviously already finalized and then someone suddenly says, okay, now is the time to get the water-puffing guys on the ground. But that's actually too late because you've already finalized your drawings, your designs, your construction process, everything is done and you're now trying to fit water-puffing into a kind of fixed geometry because you've already got the structure design in place. You already decided timelines in terms of what activity is going to happen at what stages. So many things have already been decided. Penetrations, where they are going to come in. And you are now trying to fit waterproofing around all of that. So you
Steven Pacitti: Yeah.
Mehul Parikh: are now looking at chemistry to solve a geometry or a planning problem. That's not going to work. So that is
Steven Pacitti: That's not the way to do it, yeah.
Mehul Parikh: changing. People are improving. People are looking at waterproofing a little bit more differently. And I think that's where I believe I can add impact because of the experience of doing all of this for decades. So you learn along the way. You make your mistakes. You
Steven Pacitti: Yeah.
Mehul Parikh: see other people making mistakes. And you kind of want to see if you can avoid that for the projects that are coming up. And that's what I hope.
Steven Pacitti: I think I've heard you refer to waterproofing as a fragmented industry. I wondered if you could just explain a little bit more about that and why it remains fragmented and what's likely to change.
Mehul Parikh: So it's fragmented because it's not just you know the manufacturers, water-proofing manufacturers yes we have a good set of water-proofing manufacturers that are there in India. It's fragmented because of the fact that there is no you know let's say there is no there's no defined approach towards deciding the water-proofing.
Steven Pacitti: Yeah.
Mehul Parikh: It's not brought in at a design stage. It's this very stop-start,
Steven Pacitti: Okay.
Mehul Parikh: very ad hoc basis approach that is what I was just talking about. So
Steven Pacitti: Yes.
Mehul Parikh: the lack of a professional approach like so many specialist items in a construction project go through a design like you have facade you don't just buy aluminium panels and stick them on the wall you will go through a design process for your facade for so many other things and that has been lacking so that is one thing the other thing is know a lot of the installation that happens happens through very small outfits small applicators and there is no defined system to train them to certify them. Now there are some companies like yes you know because I was part of Pidlite closely for so long and I still advise so I know that there are some professional companies like Pidlite maybe there are few others as well who are taking the effort to train applicators to certify them according
Steven Pacitti: Okay.
Mehul Parikh: to their skill sets according to their capability in terms of what kind of people do they have what kind of technologies they can apply. it's not necessary that an applicator who can apply a cementitious coating for example, whether they can also apply
Steven Pacitti: Hmm.
Mehul Parikh: a polyurethane membrane, whether they can also do a spray applied polyurethane foam insulation, those capabilities
Steven Pacitti: Yeah.
Mehul Parikh: will be different. The skill sets, the kind of supervision control, equipment that you will need, all of this is not so well available in terms of a database that you can pick.
Steven Pacitti: right.
Mehul Parikh: and you can select the application partner that you want to bring in to execute. So all that is not currently there in India so easily available for people to rely on.
Steven Pacitti: Do we need legislation, do you think, to say actually you've got to use a certified applicator? You've got to get someone who knows what they're talking about into the projects.
Mehul Parikh: So yes, there are some steps coming up, think, like for example, we have this new National Building Code, NBC 2026 that has just been published. So there are steps going
Steven Pacitti: Yes.
Mehul Parikh: forward in that direction. And there are organizations like you have the Construction Industry Development Council, CIDC. I have also been working closely with them on some water-boofing codes that they want to actually draft. And they've got a
Steven Pacitti: Okay.
Mehul Parikh: group of industry experts I am part of that group which has been working on drafting standards or codes for waterproofing applicable to India. there are steps like this that are happening and CIDC for example does certify technicians, you the actual application guys who are installing the product on the site not just the companies by themselves
Steven Pacitti: I understand. Yep.
Mehul Parikh: but the actual installers so they are certifying them in terms of their capability to install.
Steven Pacitti: right.
Mehul Parikh: There are steps that are happening, but I mean if we can do it faster then because the industry is so big, you you've got thousands of projects happening everywhere. So the pace at which
Steven Pacitti: course, yeah.
Mehul Parikh: all of this is happening and what is needed on the ground that gap needs to be kind of bridged a little sooner.
Steven Pacitti: I mean, I was in Mumbai recently and I've seen the scale of the development that is going to, is and is going to take place there. So there's huge amounts of projects, lot of pressure on getting things done quickly. It brings us nicely onto material choice, Mehul. now people often associate, of course, polyurethane with insulation foam. Could you
Mehul Parikh: Okay.
Steven Pacitti: explain its roles specifically in keeping buildings dry as a sort of a sealant, a membrane? And where does polyurethane have advantages over alternative materials?
Mehul Parikh: Yeah sure, so when you talk about water-cuffing, you will always have a choice, right? Whether you want to use polyurethane, whether you want to use a cementitious coating, acrylics, you have MMA and you have so many other, you know, polymer types and they come in different forms. You could use a liquid applied coating or a sheet membrane, PVC or TPO. mean, so the options are there. I think when you talk about water-cuffing, it all comes comes down to the design in terms of how, what is the performance expectation that you are expecting to be delivered, what is the kind of construction that is happening, what kind of geography it is being built in, what are the kind of climate impact that it is going to be expected to sustain, those kind of things need to be asked. Then the time in which is, what is the timeline? We spoke about the metro project, where you saying that you you want to build something and put backfill on quickly so what kind of time are you going to allow on the site for construction what kind of interfaces does the water roofing have to deal with different rates so all of those things need to be analyzed which is why you need a water roofing specialist because a product supplier on their own or a water roofing you know applicator or the civil contractor these are the guys who are not going
Steven Pacitti: and
Mehul Parikh: to be able to deal with those questions
Steven Pacitti: Yeah.
Mehul Parikh: you might have a basement for example with pile foundation. So you will need to do a detailing where the pile caps and the raft slab are going to interface. So all of this requires thought in terms of what product and what solution is going to fit well. The beauty with polyurethane and that's why I think many of us use it increasingly is because it's versatile. So you can use
Steven Pacitti: Yes.
Mehul Parikh: it in the form of a coating and then again you have coatings which can be one component or you can have two component coating which have reactive chemistry which take it to a higher level of performance you then have hybrids with polyurea and polyurethane which can be instant setting with even higher mechanical performance and spray applied so you can deal with large areas at a time very quickly so you have all those you know
Steven Pacitti: Yeah.
Mehul Parikh: capabilities with polyurethane you have grouts that can help you to deal with remedial water proofing should you have a leak and you want to block it you can inject polyurethane in different forms and deal with that and then of course you have your insulation with spray applied
Steven Pacitti: Hmm.
Mehul Parikh: polyurethane foam that can that sits very well on on roofs so the beauty with polyurethane is that you have all these different ways in which it can be
Steven Pacitti: Yeah.
Mehul Parikh: brought to site it can be installed on site and give you solutions and and the chemistry is also evolving so you now have not just from the formulation side but from an application point you have polyurethane which can be applied on slightly damp surfaces you have you know formulations those are
Steven Pacitti: Okay, yes.
Mehul Parikh: great because they are dealing with the kind of problems that you know India typically has you know we have high humidity in many places we have our
Steven Pacitti: Yeah.
Mehul Parikh: monsoon to deal with so those kind of conditions also we have the ability to formulate and create products so there are solutions and I think polyurethane being that
Steven Pacitti: Yeah.
Mehul Parikh: versatile product is helping to solve many of those practical issues.
Steven Pacitti: So you're obviously as a consultant, are, I would assume, sort of materials agnostic to waterproofing. You do have obviously a long history with polyurethane. And you mentioned there that polyurethane is being favored. So is there a concerted transition? other materials over to polyurethane in these waterproofing applications? Is there a big big shift?
Mehul Parikh: So I think it's because of the versatility and the kind of performance features that we are seeing. India traditionally for example, the roofs, we have been using a system, I would not call it a product, a system or a technique which is called brick-backed coba where you simply are laying brick pieces on a cement mortar bedding. Essentially you are creating a sloped surface because they are laid to a gradient and you you finish that layer on the top with another layer of cement mortar. What you are essentially trying to do is creating a surface that has know a quick runoff capability so that you water that's falling is taken to the drain points as quickly as possible and that's the general you know philosophy behind that. And then of course the brick being the kind of a little bit absorbent material should there be some you know penetration which there will be through that mortar layer it will kind of retain some of that moisture for a little longer time without allowing it to straight away go down to the slab plus
Steven Pacitti: Yes.
Mehul Parikh: the brick has a bit of a know it's a better insulation properties if you may call it that compared to you know just leaving the slab open so those
Steven Pacitti: Yeah.
Mehul Parikh: kind of things have been traditionally there and polyurethane is now the obvious solution one of the reasons is over time construction projects have become bigger roofs have become larger earlier you might have a 5000 square feet roof which was considered a decent size today you have large commercial roofs you have data centers and so many different types of the construction has evolved
Steven Pacitti: Yeah.
Mehul Parikh: and with those large roofs you have IT buildings you know information technology centers and all of that they have typically 30-40 thousand square feet roofs 3000-4000 square meters now those roofs are going to move or going to experience movements
Steven Pacitti: Yeah.
Mehul Parikh: because of the climate what it is going to throw at you. So you
Steven Pacitti: Yeah.
Mehul Parikh: are going to see daytime temperature changes and all of that translating into the need for a far more flexible system, far more resilient system on the roof. And
Steven Pacitti: Yeah.
Mehul Parikh: Brick-Bad-Coba or some of the traditional methods have been rigid. have not been able to, they can't deal with the
Steven Pacitti: Yeah.
Mehul Parikh: flexibility requirements. Polyurethane inherently is flexible, the liquid applied. membranes will have far better tensile properties and elongation and all of that to deal with the movements expected. So
Steven Pacitti: Yeah.
Mehul Parikh: that creates a reason for acceptance you know because people realize
Steven Pacitti: Yeah.
Mehul Parikh: that the older techniques are obsolete now there is time to move
Steven Pacitti: Yeah.
Mehul Parikh: on and the first progression from that very old Brigbad Koba method was to use cementitious coatings as an underlayment. So you would still have Brigbad Koba sitting on top
Steven Pacitti: Yeah.
Mehul Parikh: but you would have a cementitious coating a polymer modified cementitious
Steven Pacitti: Hmm.
Mehul Parikh: coating as the kind of water-boofing system below that. Now,
Steven Pacitti: Yeah.
Mehul Parikh: while it was a step forward, cementitious coatings again will have very limited flexibility. So the next step was then people started looking at acrylics. But acrylics are not as resilient to long-term water exposure as a polyurethane liquid membrane will be. So
Steven Pacitti: Right.
Mehul Parikh: when you look at those kind of performance expectations, ability to resist hydrolysis for example or dynamic crack bridging, effects of long
Steven Pacitti: Hmm.
Mehul Parikh: term water bonding. All of that polyurethane generally tends to provide you formulation that can perform in those demanding environments and that's how I think over time the acceptance
Steven Pacitti: Yeah.
Mehul Parikh: towards polyurethane has been improving.
Steven Pacitti: And it's interesting, isn't it? Because I we see, I mean, in the UK, we've had issues with spray foam in loft spaces. We've had
Mehul Parikh: Mm-hmm.
Steven Pacitti: this push to have insulation into your cavities of houses to improve energy efficiency. But there's a lack of maybe understanding at government level sometimes in terms of the material science and the fact that actually what you're doing by creating something that is so sealed is that you're not allowing airflow, It has to be breathable. Otherwise you're going to get all sorts of damp and mould problems. And I think maybe it's getting that material science education to those kind of levels. And maybe the associations, are part of that education to enable the building standards to improve overall, would you say?
Mehul Parikh: Yes, that's true. That's true. So mean organizations like CIDC or Indian Concrete Institute, there are so many such industry bodies and
Steven Pacitti: Yeah.
Mehul Parikh: there's a lot of, so you have for example Waterproofers Association of India and they just had a seminar
Steven Pacitti: Okay.
Mehul Parikh: a couple of months back. So there is a lot of, you know, technical knowledge being shared more widely now. So that is helping the, you know, acceptance of good specifications, good techniques. People are understanding that, you know, it requires a professional approach not just you know a cut copy paste approach that that kind
Steven Pacitti: Yep.
Mehul Parikh: of awareness is slowly coming in and for example you have the Indian standard IS 16471 which is meant for substructure water roofing but that's where construction typically will start and you also
Steven Pacitti: Okay.
Mehul Parikh: have then the British standard BS 8102 now standards
Steven Pacitti: right.
Mehul Parikh: like these for example clearly recommend that you need to have a specialist, a water-boofing specialist as part of the design team.
Steven Pacitti: Yep.
Mehul Parikh: And even this new national building code, NBC 2026, it also talks about the fact that you need subject matter experts as part of a design team in a project right from the early stage, right from
Steven Pacitti: Understood. Yeah. Yeah.
Mehul Parikh: the design concept stage. And that's where, you know, acceptance is coming in, you know, that yes, we need to think of water-boofing not just as a product that you just simply you know bring to the site and get someone to just apply for but think about it in terms of how it will
Steven Pacitti: Yeah.
Mehul Parikh: fit a particular project. So
Steven Pacitti: Yeah.
Mehul Parikh: it's early days I would say the some of the institutional developers you know the larger structural consultants the more evolved architects all of these and project management companies these are all slowly realizing the need for this specialist approach you know and yes
Steven Pacitti: Yeah.
Mehul Parikh: so you know it that's the way think a market will move you will have some of the you know aware people taking that step forward and then a larger market will follow that yes this seems to be the obvious right path towards designing things on a fit for purpose project specific basis
Steven Pacitti: You touched upon some of the changes behind the scenes I was looking at, the Energy Conservation Sustainable Building Code, the Residential Eco-Newas Samhita. I've probably butchered the way of saying that, the Energy Efficiency Code for India, for residential buildings. They provide
Mehul Parikh: Yeah. Yeah.
Steven Pacitti: an important backdrop to that. Are energy performance requirements changing how if we focus on roofs, how they're specified so we're bringing insulation and waterproofing together or are they still largely designed and purchased as separate packages? Is there more
Mehul Parikh: Yeah.
Steven Pacitti: of an integration of those systems?
Mehul Parikh: No, so that's I mean that's true in both ways. First is that yes, we have now, you know, these building codes, for example, or the regulatory documents like you have the ECSBC, the Energy Conservation and Sustainability Building Code that was published in 2024 ECSBC 2024. And that clearly, so that's focused on commercial buildings. Firstly, it's not something that is applicable to every construction project but it's applicable to commercial buildings largely above a certain energy consumption criteria that it defines but the good thing is that it is applicable to all those commercial buildings which are larger than that threshold value. So most buildings do get covered, the ones that are typically built to house large offices or institutional buildings for a corporate office or a shopping mall or a hotel for example. a hospital, an educational college, government office, all of those kind of buildings by default will get covered through that ECSBC 2024 criteria. And the good part is that it's talking about the fact that it's not just that insulation should be there. It's very clearly talking about it. If I remember, it's the clause, I think it's in chapter 5, 5.3.1, if I remember it correctly, that's the clause that talks about insulation having to be an over deck insulation applied on the top of the roof not an under deck insulation. That's another
Steven Pacitti: I see. Right.
Mehul Parikh: change because in India historically a lot of buildings have been insulated particularly the air conditioned buildings because there was an obvious need to do it you know from a HVAC point of view for example but they used to be typically under deck because that was easy you know just take insulation from below and you thought that you're getting a good insulation but slowly people are realizing that like you block water from the source you have to obviously also block heat from the source and if it's coming from the roof downwards then you're better off putting insulation on the top of that roof and kind of protecting that roof rather than allowing heat to get into a building and then
Steven Pacitti: Yeah.
Mehul Parikh: trying to you know block it from underneath so that kind of realization has come ECSBC has given that bit of push also and even before ECSBC we had of course green building so we have a lot of commercial buildings and increasingly a lot of residential buildings also because there are some incentives that come with those certifications and green buildings typically tend to have energy efficiency as one of the essential elements. So yes the
Steven Pacitti: Yeah.
Mehul Parikh: roof insulation has been kind of picking up along the way and while it's happening the first approach was to answer the second part of your question is whether it's dealt with separately. So yes from a procurement angle or a commercial angle the procurement teams would not recognize the fact that when you are putting insulation on the top of a roof it is now part of a roof assembly. It's not just another layer sitting there along with other
Steven Pacitti: Yes.
Mehul Parikh: things and it has to integrate with water roofing. So previously there have been a lot of projects which have been tendered out with insulation just as a separate line item so people would want to buy the insulation or source it. from someone who supplies insulation and then find out that you know on the ground the interface between insulation and water proofing will not be taken care of by one person if you have multiple people but those failures have happened people have done that mistake got insulation got it to the site through someone else got a water proofing guy to do their job and then suddenly realizing maybe a year or two down the line when something leaks that whom do you catch hold of and then obviously is passing the buck going to happen so Today specifications are evolving, they are getting better
Steven Pacitti: Yeah.
Mehul Parikh: and people are integrating the roof insulation and waterproofing together. So it's still I would say early days but realization
Steven Pacitti: Yeah.
Mehul Parikh: is coming in that you have to look at it as a roof system because the roof is going
Steven Pacitti: Yes.
Mehul Parikh: to take care of heat insulation, know, waterproofing, the movement that are going to happen. There are drainage outlets that need to be detailed. You increasingly have solar panels being put on a roof so they will penetration that need to be sealed around. So it's a complex
Steven Pacitti: Yep.
Mehul Parikh: you know affair and that needs to be dealt with with right expertise.
Steven Pacitti: And coatings as well, if you're coating a waterproof membrane, that is then exposed to UV, to the conditions of that particular region. are coatings of replaced when they should be generally? I guess they have a lifespan of maybe 10 to 15 years under UV. So are those things being done? because obviously that can then lead to failures if you're not maintaining.
Mehul Parikh: Yeah. So that's again a very important point. So over the years, people have not really in the past looked at maintenance or maintainability
Steven Pacitti: Hmm.
Mehul Parikh: as something that should be even thought of. People would
Steven Pacitti: Yeah.
Mehul Parikh: say that, okay, I've got this insulation done, I've got the roof completed and that's the end of it. But it has a life, and especially when you have occupied buildings, you don't want to go up and kind of rip open the entire roof. and then redo everything because in a functioning hotel for example or an office or even if it's a residential apartment you don't want to inconvenience the occupants or disrupt operations or you know sort of affect your revenue for example a hospital
Steven Pacitti: Mm.
Mehul Parikh: or a hotel you can't shut off floors simply because you want to now redo the waterproofing of the roof so
Steven Pacitti: Yeah.
Mehul Parikh: people have been now thinking about it earlier those mistakes have happened and I think that's where roof refurbishment is going to be a big let's say area area of
Steven Pacitti: Okay.
Mehul Parikh: growth it already is showing up that way because what has been constructed in the past because of what we spoke about earlier you know the lack of a very systematic approach towards the design and everything a kind of cut copy paste or older techniques which are obsolete all of that is now slowly showing through you know and another important thing is our climate is changing so no matter you know it's not just about products or it about whether we approach the construction correctly. The fundamental issue is climate is changing. So I was at a climate, I was at an event of Deloitte in October, I think 25 about a year back or so and they were launching a climate report. Okay. An India specific climate report, not some global report that had India as a footnote there, but it was actually an India specific climate report. And what I remember from that is that we are seeing almost a 1.4x increase in extreme rainfall events in India in just the last five years. And I stayed in Mumbai and there are places across India like Delhi for example, Hyderabad, all of these places which were earlier not known to have very severe monsoon risk in
Steven Pacitti: Hmm.
Mehul Parikh: that sense from the water moving point of view. But they are seeing those very very heavy intense rainfall days. So 1.4x increase in extreme rainfall. events in just five years is one observation that is there. The other pertinent observation I found was the fact that extreme heat events across India, especially in our summer months, March to say May for example, and also then later on in the year around September, October. So these extreme heat events have also gone up by I 15 fold in the last three decades. Then you also have our long period average rainfall rainfall what we call so across central India so Delhi is obviously part of that so this report also captured that and if I remember it's about 40 % more so about 1100 mm typically has now gone up to about more than 1500 close to 1600 mm of rainfall so with all of those things the climate is demanding that the water-boofing systems on the roof or elsewhere in a building which is going to you know deal with all of that have to be designed far more robustly you you can't have things that happened 30-40 years ago, continuing to deliver the solution. And that's where the maintenance element comes in. Because the climate is going to do what it is going to do, you will have to look at some levels of redundancy in the specification build up in terms of layers or solutions that you are integrating into it and also the fact that how are you going to maintain. Because you will need to go
Steven Pacitti: Yeah.
Mehul Parikh: back and reapply some sort of a top coat on a roof. that is it going to last you for the next 100 years it won't so 10 years 15 years down the line you should be able to go back and apply something on the roof that keeps it sealed nicely from you know water ingress and helps to protect the investments below in terms of whatever finishes
Steven Pacitti: Yes.
Mehul Parikh: or functionality you have so yes that's going to be the way forward
Steven Pacitti: Yes, I understand. I wanted to ask you about the Indian government's draft that they proposed in June of this year for a mandatory rating framework for new...
Mehul Parikh: Yeah, the B-E without energy efficiency.
Steven Pacitti: So that's to cover new commercial office and residential buildings of at least 20,000 square meters, I believe.
Mehul Parikh: Yeah, I remember I think that's what it says,
Steven Pacitti: Would that kind of requirement, will it change specification decisions when it comes to materials, do you think? Or will enforcement be the bigger issue here?
Mehul Parikh: See it is definitely going to change and it is going to impact and even if you go back in fact to the ECSBC, the Energy Conservation Code, even ECSBC apart from asking you to put on insulation on the top is also asking you to either put a vegetative roof on I think it's about 90 % of the exposed roof for example, exposed areas
Steven Pacitti: Okay.
Mehul Parikh: of the roof other than where have your MEP or HVAC equipment settings other than your utility areas the rest of the exposed roof should either be a vegetative roof or it should have
Steven Pacitti: Okay.
Mehul Parikh: a high SRI reflective coating on the top. Now
Steven Pacitti: I see.
Mehul Parikh: if you are possibly looking at a vegetative roof for example the water boofing requirements for a green roof a landscape roof are going to be of an elevated nature in terms of the whole performance element to it you know and
Steven Pacitti: Hmm.
Mehul Parikh: when you say high SRI coatings yes you have acrylics that do the job but when you have foot traffic ability that you are dealing with along with you know along with the fact that you want a good you know SRI value to it hybrid coatings which polyurethane blended with other polymers you know those hybrid solutions actually are going to be better you know doing that
Steven Pacitti: Yeah.
Mehul Parikh: So yes, some of the codal requirements or standards
Steven Pacitti: Yeah.
Mehul Parikh: are going to push performance expectations higher, which is good because we will end up building
Steven Pacitti: Yeah.
Mehul Parikh: better. see, when we talk about sustainability, the underlying part of all of these standards or regulations is pushing construction towards sustainability in some form. When we say
Steven Pacitti: Yeah, yeah.
Mehul Parikh: sustainability, very big word, you know, and I'm not here to define what it stands for. Each one has their own sort of view towards it. My simple thought is that durability and sustainability go hand in hand.
Steven Pacitti: Yeah.
Mehul Parikh: So if you are going to look at sustainability or wanting to have more sustainable buildings then durability is the key. You will have to have things that are going into the
Steven Pacitti: Yeah.
Mehul Parikh: whole construction process, water roofing obviously a critical part of it which are going to last for a longer period not having to repair or replace them frequently enough. and thereby conserve resources. So it's all connected in that sense,
Steven Pacitti: if we talk about a building project, when it comes to the handover stage, what objective evidence then should a building owner receive to show that the waterproofing was installed properly?
Mehul Parikh: Yeah, so I think that is very important because again going back to what I said the RERA, know, the regulation that we have in India talking about the five-year defect liability that a developer has to cater to and manage. So if you look at all of that, the traditional approach in India or maybe possibly across the world is, you get a warranty document, right? A water-proofing 10 years warranty. A warranty is obviously a commercial contract, right? It's basically saying that look, you know, if something goes wrong, that warranty will enable you to get some solution towards it. But it has to start with a proactive and a preventive sort of scientific approach that whether things have been done correctly or not. And that's where again, I think a water-proofing specialist coming on a design team is important because they will put in that framework, that whole framework in terms of not just the specification, but what is going to happen in terms of checklists that will be followed, what kind of records are going to be kept through the life cycle
Steven Pacitti: Yeah.
Mehul Parikh: of the project and be part of a handover document. So things like your batch test certificates or material test certificates that a manufacturer provides with every batch of material that comes in or even before that when you are pre-qualifying and approving products and even the water
Steven Pacitti: Yep.
Mehul Parikh: in contract, what kind of capabilities were looked at. you know, in terms of their ability to execute a particular project or the compliance of the product to the specifications or what kind of third party testing data was available on record to show that yes, this
Steven Pacitti: Yeah.
Mehul Parikh: product is going to do the job that is expected from it. And then you have all those quality checklists in terms of, you know, wet film thicknesses that are checked on the ground, surface preparation, how has it been done correctly or not, whether the detailing
Steven Pacitti: Yeah.
Mehul Parikh: around penetration has been done. And you know there are a lot of free tests that normally should I think should be done you know like wet film thickness or you know you should be testing adhesion to check whether the surface preparation is good enough to receive the coating over it or not. You can't just simply look at visually and say okay this looks fine to me let me go around applying the coating it will probably not work.
Steven Pacitti: Yeah.
Mehul Parikh: So all those data and then finally the know the flood tests or any other test that you have done to prove that the water gophing is effective. Flood tests generally
Steven Pacitti: Yeah.
Mehul Parikh: are most commonly done but they may or may not be the only solution. are newer techniques available. Some projects are adopting those. So all those checklists of handover, takeover between trades sequentially, all of that data
Steven Pacitti: Yeah.
Mehul Parikh: I think should go in finally with as-built drawings. That is a missing piece. I tell you a lot of projects today are following maybe 80 % of what I just said. Okay, the bigger projects. Not all I would say but the bigger projects being done by more institutional companies you know larger EPC contractors and all will have about 70-80 % of these items being done but the single biggest piece that I think is grossly missing across a vast majority is as-built water-puffing drawings. So you will have very rudimentary schematic drawings that get you know that get submitted at the initial stage by the know water-puffing contractor or sometime by the manufacturer, but they are not representative of the actual site. They are just very typical schematic things, know, outlining how the water moving is likely to happen. But eventually what has happened on the ground, right, which is project specific, how the details have been actually worked around, all that should come in the form of as-built drawings, which are not there. So you ultimately don't know whether water moving has been done in all the areas prone to risk, which was the first thing that I said that we don't analyze. risk sometimes we miss out areas you know we don't waterproof areas
Steven Pacitti: Yeah.
Mehul Parikh: which should be waterproofed so that whole risk assessment whether it was done correctly and eventually it has to show in terms of on the ground what was executed so all
Steven Pacitti: Yeah.
Mehul Parikh: this has to be there that's when I think a project owner or the people that the project owner hands over the documentation to you know your main your facilities managers basically all of those guys
Steven Pacitti: Yes.
Mehul Parikh: will know what was done and that be easier to do a kind of analysis is if things were to fail you will be able to trace that path backwards you know in terms of that whole journey of water proofing
Steven Pacitti: Yeah.
Mehul Parikh: right from the system selection to the execution you will probably have a better chance of finding out where things might have gone wrong and hence rectify things more easily.
Steven Pacitti: I wanted to just touch on raw materials I talking about this recently in Mumbai at our show, about the role of localization and India's domestic feedstock abilities and capacities. How exposed is Indian polyurethane waterproofing to imported feedstocks and additives? Is there an area where localisation is actually making a meaningful difference?
Mehul Parikh: So look, mean the honest answer is yes India, you know, we don't have any meaningful domestic MDI production, for example, right? And we are dependent on imports for a lot of the core raw materials, whether it's MDI, TDI, whether it's, you know, specialized polyols, We are import dependent on that sense and the vulnerability is there Sometimes it works in our favor because I think you know at times when European prices go up if China holds its price Then it's something that helps us to you know, but that's all short-term and it's not reliable in that sense so I think what has rather than the actual raw material manufacturing capability. think what India has been doing, know, and again, think, PdLite, of course, because I have been part of that, but there other companies also who have been actually developing formulating capabilities. So we are able to, yes, deal with sometimes important materials, but
Steven Pacitti: Okay. Yeah.
Mehul Parikh: getting them to, you know, getting a more meaningful formulation out of it. So it's not just relying on a product that is, let's say, honestly made for a European climate, just bringing it to India and putting it to use on a far more stringent or more aggressive climate that we will have in many places. So lot of these guys in India are actually doing some meaningful formulation efforts and coming out with products which are more suitable to being applied on Indian conditions. For example,
Steven Pacitti: Yeah.
Mehul Parikh: I can just give you this one example not intending to push a product or anything because I want to be brand agnostic but the fact is that know the Pidlite has something called Wonderproof 100. Now this product why is it exciting is because it's a primer less product. It can be applied without a primer on multiple subsets.
Steven Pacitti: Okay.
Mehul Parikh: So it's not just on concrete for example. It deals with the fact that on a roof you will have penetrations which are going to have let's say a PVC pipe for drainage or you have this know solar panel installation with a metal you know fastener or something that's going through the roof. So a product that can be applied without a primer on these multiple substrates, right, also deal with a slightly higher moisture content than
Steven Pacitti: Hmm.
Mehul Parikh: most polyurethanes will allow for and it is kind of rain proof within about an hour or two. So once you apply an hour or two later if it rains, it's not going to get washed off. plus it's UV resistant
Steven Pacitti: before I move on to a couple of sort of final lighter questions for a bit of fun, for any, polyurethane producers and, and formulators that might be listening to this podcast, what is the one, what is the one problem
Mehul Parikh: Thank
Steven Pacitti: you would most want them to solve that would make, the biggest difference on a construction site.
Mehul Parikh: See, I mean, I can have a laundry list of... things that you know coming from a practical point of view you know I am not a manufacturing let's say you know expert I have executed water roofing works so I come from that practical sense and that's where you tend to you know want the moon you know in terms of all your sort of know wish list for example but I think see if we can if we can build products you know if we can continue to formulate and build products which are capable of performing in India and I am talking about India because that's my area of work basically. So as long as you are able to have something which is genuinely tolerant of residual moisture because see that is one thing that in India you are going to be faced with. And it's not just the monsoon, the other problem is that on construction sites the developers or even the construction companies they don't give you like know 20 days or longer to wait for water buffing. They literally will cast the slab and say okay you're on it tomorrow you know so
Steven Pacitti: right.
Mehul Parikh: whether you like it or not the fact is that you have to deal with those situations so I would love to have a product that can actually do you know its job in terms of a proper cross-linking you know density that is expected
Steven Pacitti: Hmm.
Mehul Parikh: to be achieved with obviously the specified DFT and all in place but something that can be applied on a damp surface actually. without pinholes and all of that and if we can you know bring in some system that is also little intelligent you know because right now water-boofing systems are generally dumb is what I believe right you are expecting you know ways and means to check it to ensure whether it is done correctly so is there some intelligence there's so much you know we are in an AI world so I don't know maybe I'm asking for too much but is there some intelligent fabric for example of increasing the water-boofing systems are reinforced but we putting just a know a reinforcing fabric or a fleece
Steven Pacitti: Mm.
Mehul Parikh: you know to kind of enhance its mechanical properties that's what is being
Steven Pacitti: Yeah.
Mehul Parikh: done but while we are doing that can that fabric have some electrical grid in it which can sense a breach in the water-boofing system or when water comes in contact so obviously there's a breach and the system is not performing is there something
Steven Pacitti: Yeah.
Mehul Parikh: that can trigger an early warning reaction so even before you have let's let's say the manifestation of leakage in terms of water coming down, you are able to address a problem or being able to identify it. So let's say that it may not give you an early warning alert, but even if it can kind of mark out that problem and there can be a separate tool that is able to walk on the roof for example and it can kind of
Steven Pacitti: Yeah.
Mehul Parikh: connect with each other and say, okay, this is where the problem is. So some intelligent sensor which can be integrated into the system. Something like this you know. Maybe it's asking for too much but.
Steven Pacitti: If anyone's listening and has answers to Mayhul then drop me an email. Mayhul, I want
Mehul Parikh: Thank you.
Steven Pacitti: to finish with a couple of quickfire questions if I may just for a bit of fun. So I mean you've obviously seen a lot of roofs, a lot of buildings in your
Mehul Parikh: Thank
Steven Pacitti: time. What's the most inventive and perhaps least convincing attempt to stop a leak that you've ever seen?
Mehul Parikh: I will tell you funnily people have been using jaggery solution. You have
Steven Pacitti: What's that?
Mehul Parikh: jaggery sugar, jaggery.
Steven Pacitti: okay. Right, right.
Mehul Parikh: So people have actually used jaggery solution mixed with cement on the roof. as a very primitive rudimentary water roofing and you will be finally surprised that it sometimes actually stops water maybe for a short time but it actually does that you know so people have gone around applying you know that kind of thing
Steven Pacitti: I suppose yeah it's novel ideas but you know it's all science. Have you ever walked into a building, Mayhill, looked at one detail and thought, do you know what, I'll be back here after the monsoon.
Mehul Parikh: yes, it happens all the time. It happens all the time. And sometimes, you know, I've actually been called to, you know, I can't name buildings obviously or projects, but I've actually had that experience many times.
Steven Pacitti: Yeah, I've learned a lot today about waterproofing. So thank you so much for your time, Mayhill.
Mehul Parikh: Thank you. Thank you, Stephen. It was wonderful.
Steven Pacitti: You
Mehul Parikh: Thank you,
Steven Pacitti: been listening to Polycast by UT, helping your business expand in all the right places. We'll see you again soon.
