Understanding Air and Vapor Barriers INSIDE your House

on the build show today we're gonna be talking about vapor barriers do I need one do I need it on the inside or the outside we're gonna get into some good building science today and oh by the way I'm coming to you from this sigue headquarters in Switzerland I've got a great wall mock up behind me we're gonna be talking about a fantastic tour I took this is a really good episode let's get going [Music] the build show has been on the road we're in Switzerland and hopefully you saw our other videos we visited some incredible job sites over the last couple days to see how they build in Switzerland now today we're at the sigue Factory and if you know this company this is a Swiss company that makes some incredible products a lot of them going to the passive houses they're being built to some of the highest standards in the world right now but we're gonna be on today's episode getting into some geeky building science but before I do that I'm gonna bring on to their trainers this is David and Andrew from sigue and they're gonna be installing not a traditional vapour barrier for us but a directional vapour control layer this is a product very special only sigue has it it's called my Rex and these guys are gonna be installing it while I give you some basic building science we'll come back to them in a minute while they're installing the background now first before we get into this let me start at the basics because not everybody watching this knows exactly what we're talking about what are the four things that every house needs the control there's really four major elements of nature that every house has the control and of course the first one is water if we don't control water it's all over for houses start leaking we're gonna end up having problems in the houses to begin with so we need to control the bulk water that's the rain that's the snow the ice all the things that are coming down from the sky number two just below that is air we need to control air movement you know when I was a kid my dad used to always say what do you think we live in a barn close the door son I'm paying for that heating now we're here in Switzerland it's 10 degrees outside right now if we left our doors open and don't control that air we're gonna use a whole lot of heating and we're gonna use a lot of cooling in the summertime if we don't control the air number three we need to control vapor and that's probably why you may have tuned into this episode because we're talking about vapor barriers vapor VIII APO are now vapor this is something we've heard about a lot right I've been a builder for 25 years when I started in construction the only thing we use for a vapor barrier and I was building in the in the Northeast is we use plastic we use visqueen we'd put it up on the walls right before the drywall guys came and that would control vapor flow into our walls now in a cold climate we need one of those and I'm gonna get into that a minute but that's the third thing we have one more thing that our houses need to control that's thermal this is insulation this is heat flow right if we don't heat our houses in the wintertime they're gonna be awfully cold and if we don't have any insulation in the walls we're gonna have huge bills this lit this order of importance though we need to respect right water really is more important than air if we don't control water it doesn't matter if we've got on the air but air is really more important to control in some respects than vapor and if we don't control these three it doesn't really matter how much insulation or how less insulation we have okay now let's look at a building envelope we talked about this as building scientists all the time the envelope the walls of the house the roof of the house here's a slab on grade house here's your walls transitioning white to a roof and we've got insulation in the walls right controlling the thermal and we talked about water the most important thing a house has to control and that water comes down from the sky and needs to run off but what about air control on a house you know in the wintertime if our windows and doors are leaking and if we have some leakage around penetrations like our see our chimneys in our houses with the stack effect meeting with that heat rising we're going to get a lot of air movement through our houses and that can not only be drafty and uncomfortable that can cost us a lot of money in our energy bills and when that heat leaves the top here what's gonna replace it cold air in the wintertime coming in through those air leaks like between the slab and the framing that's gonna bring that cold air in and it's gonna drive up our energy bills and it's gonna also drive a lot of discomfort now when that air leaks through the house think about this penetration here that may be leaking a little bit of air inside in the wintertime it's going to be hot it may be a little bit humid in there too because we're cooking we're bathing we're cleaning we've got all this moisture in our houses as that air leaks through and it ends up leaking all the way to the outside what do you think it might find it might find a cold condensing surface which could lead to moisture depositing inside our walls and what happens when moisture deposits in a wood friend house that can lead to mold on the converse for that if water comes in from the outside and we have a roof leak let's say in our envelope whether that's from a roof or a window same thing can happen mold can happen in our houses okay next airflow and diffusion getting back to this vapor barrier thing which is why you're watching this video where do we need the vapor barrier how much control do we need to make over it now there's two ways that vapor can move through our walls right diffusion is one method we hear about this all the time what's the prom rating of your house rap or how much water can actually move through a material through diffusion now I stole this from Joe Steve Rick at building Science corporation this is one of his diagrams that I'm basically using here but let's say this is a four by eight sheet of drywall in four and a four by eight sheet over the course of one winter how much water can diffuse through there which means it actually goes through the cells and and the material itself about a third of a quart how much is a third of quart hmm it's about that much right there that's about how much water over the entire heating season might diffuse through the wall so what do we need a vapor barrier yeah we'd probably do we want to stop that movement but on the other hand what about air moving through that same thing what if that same four by eight sheet of drywall means my little cool Siegen knife air what if it had a little one inch by one inch square hole there if I can make it square without cutting myself what if we had a little hole in that drywall do we have holes in our walls of course we do we have wire penetrations we have electrical fixtures we have all kinds of things penetrating our drywall in our houses on American houses four by eight sheet one-inch square hole how much water you think is gonna go through there compared to the diffusion devyn how much water do you think it is it's this much right here instead of a third of a quart it's actually 30 you imagine these 30 water bottles dumping into your wall over the course of a heating season that's a big deal thanks brother so we need to make sure that we don't have air movement and in fact air movement is in some respects more important than the vapor barrier remember when we talked about diffusion which is your vapor barrier we can get a third of a quart but when we get into air leakage through our wall so we can get a lot of water through our walls and that accumulates in our framing and if that gets to the point where it's too much that's where problems occur so air leakage is actually a really big deal and that's why what these guys are doing over here is really interesting now they're using a very cool and a very high-tech membrane for this but what they're also doing is they're doing all the details right from an air sealing perspective they're using that vapor barrier on that ceiling there they're installing it in a method that they've really thought about all the air sealing details and that is what we want to talk about today is how do we get a really airtight house that also has gotten the vapor correct on the house now I'm gonna step off for a second let these guys finish up I'll be back in just a minute okay guys I'm here with the guy who brought me all the way overseas here to Switzerland this is Patrick Hockey Patrick thank you so much for bringing me what an incredible couple days I've had now little introduction Patrick is actually a former master carpenter he grew up in Germany and was a carpenter for almost 15 years before he joined sigue and now he's the top dog on sales now Patrick tell me what's different about your company well seiga has a vision we strive for a world of zero energy loss buildings and every zero energy loss buildings needs a high-performance envelope sorry this is what seiga is specialized in so we produce high performance tapes adhesives membranes for building envelopes we develop them unique products with added value for buildings and builders of course we produce the products ourselves on our own machines self-developed machines with the Toyota Production system and then once we have produced them we retrain the installers we give training and advice in all our different markets and countries and then make it happen because the best product would fail without the proper application boy that's for sure therefore that's really the crucial part of our work no doubt and I'll tell you that's one of the things that I've loved about this visit these two guys who did this install for us we didn't spend any time with them but tell me about those guys in their role in your company well Andrew and David they are two of our trainers that we have and you must mention that sigue has an overall staff of 500 people and 260 of them are working in the field in training advice and of course also as sales reps but they do training building site trainings lunch and learns workshops with all our customers in the world to make sure that they know how to work with the product that's really cool and you guys have a very specific manual which I loved learning about today and that global air tightness Academy that we spent some time on today learning about how to use the products how to get a proper air barrier how to get a proper vapor retarder how to do all those correctly and use every one of your products and you guys have really specialized you have products that would be used in Switzerland and products that would be used in American construction as well tell me about your the plant tour that we took today in that kind of how you guys actually build the products that that we're using out in the field well since we know the demands from the different markets we gather all that information in our R&D department and then we we develop the product specific for the demands that we have and then of course with our local people we can apply the application technique of the products to the specific demands of the market also respecting the climate that we have in these different regions for example yeah now one of the things that we talked about today in the conference was how your adhesives were different then some other users out there tell me about that but the adhesives that's an water-based acrylic glue which is etching resistance that's the most important property of the product because you would expect that to last for like decades for generations and therefore it needs to be solvent free free of racing's or VOCs for example just also for a healthy climate and for durability of the products and that's that's the basis of this top-secret glue of course that the unit and and speaking of glue we spent some time in the lab today talking about stickiness now this is hard to define of course when we when we as a builder and we get a sampling on something you stick it to your hand and you kind of see how sticky it is but you can actually measure that stickiness and we saw a demonstration for instance today of one of your products my coat where they have an overlap layer on that where you pull the tape you put two layers down and we could actually you actually lift it a guy up with that tape also saw a photograph of the two owners of the company this is a still a family-owned company started in 1966 tell me about that photograph you know what I'm talking about right well they they are on a forklift upside down and and the forklift carries like a wood panel and they are sticked with their boots from from from the bottom to that panel and then hanging there like upside down just with your tapes yeah very cool very cool Patrick thank you so much for having me super impressive company you guys have some impressive people some impressive processes and I'm excited to see how your vision of a zero energy loss building is gonna translate to the rest of the world I know the people that watch my build show are like-minded they're interested in building better they may not have seen all those techniques and so it's really fun to come here and be able to show people how things are done in Switzerland because you I think you guys and some respects are a little further along and developing those really durable really energy-efficient buildings but we're coming on strong and in America and we've got a lot of Canadian viewers as well so we're not far behind thank you so much for having me Patrick you through welcome I really appreciate it guys we learned a lot about sigue but let's go back to the original question which is where's the vapor barrier go how much you need what do we do about stopping moisture and vapor in our houses so first off as you seen we're here in Switzerland this is a cold climate very very similar though to a broad swath of North America right if you're building in Chicago if you're building in Boston or Vermont or really anywhere just about in Canada your climates pretty darn similar to Switzerland it's a cold climate it's mainly Heating dominated climate you might have air conditioning but you don't need it a lot and so you want something to stop vapor from diffusing through your walls and into your framing you also want to make sure that you're stopping air flow at the inside and that's why I really like this demo these guys did for us earlier because they've got what we call a vapor barrier but it's really not a vapor barrier it's stopping the flow of vapor and this one happens to have some really cool technology where it's only going one way I don't want to get into all the sales enos on that but check out the link in the description below to hear more about that my Rex it looks like mad Rex but you don't pronounce all the letters so it's actually my Rex anyways we do need something to stop that vapor from getting into our framing because if vapor or more importantly air which is gonna carry vapor gets into our framing a lot of bad things can happen so you do need one if you're in a cold climate okay guys hopefully you caught the building science we got into the basics I didn't get into every single detail or every single climate but hopefully you learned something today big thanks to my friends at Sighet for bringing us all the way over here joey and jordan joined me we've toured some amazing job sites make sure you check out our other content and if you're new to the build show this the first time you've watched it hit that subscribe button below we've got new content every Tuesday and every Friday I've also got more from Switzerland and we're actually heading next week to the BAL show in Germany so we've got some really cool stuff happening here in Europe folsome Twitter Instagram all those we'll see you next time on build show [Music] you

Channel: Matt Risinger

Views: 456,312

Keywords: Siga, siga tape, majvest, vapor barrier, building science, siga swiss, interior poly, build show

Id: FXXgjvOJcYI

Length: 16min 4sec (964 seconds)

Published: Tue Feb 12 2019