Vapour Barrier Installed Correctly - Walls and Cold Roofs

air vapor control layers installed correctly i actually set up this rig so that i can demonstrate all sorts of things and one of the things i wanted to ins uh to show you is how to install an air vapor control layer not only on walls but on a cold roof and i've got to say to you i don't do cold roofs i only do warm roofs building control says warm roofs are the way to go and you should stay away from doing cold roofs but everybody seems to want to do especially in loft conversions they want to do cold roofs and that means that you've got to put an internal vapor barrier an air vapor control barrier that means that above this you've got your insulation and you've got through movement of of air backward and forward and this has got to be completely airtight the same as the walls the walls have got to be completely airtight now i'm i've sent thousands of photographs and and videos of different people doing air vapor control layers and and in the background you can see a few things first of all if it's not green it's not an air vapor control layer if it's plastic it could be something else some of the material ones might be silver and all sorts of different colors but green is the industry color for an air vapor control layer and if you look at what's going on here you can see all this black tape this black tape is here it's a butyl tape most of these systems that these manufacturers are using have two or three different tapes that they use and mostly are butyl tapes they might be sold in different variations but they're nearly always based on that and these tapes are really sticky there's a a piece here that i've got on a piece of wood not only does it stick to to any stud work really really well but i mean look how that has grabbed hold of that i mean that is really sticky now when you put a screw through because everybody says to me but it's not airtight because you're going to be penetrating it with screws you're going to be screwing over the top of this or you're going to be screwing over the top of that with insulation and plasterboard and you're penetrating it all the time well just here you can see i've done this video of me putting a couple of screws in through here and as i pull this screw out you can see that that the the uh the black tape has now the butyl tape is now all the way around that screw so it it self heals itself as it goes in now i've got to say that when i did this i wanted to do the whole area and then do an air pressure test on it but unfortunately i ran out of materials the amount of tape that you use this i have two rolls of this and as i went around doing it all the way around i started to run out i realized that i couldn't do that so i can't air pressure test this however i can say to you that once you do do it correctly with all these tapes all the way around you can you can start to see why it is important to make sure you're using these tapes not only is it taped everywhere where it's going to get screwed all the way through but when we get to the junction when i did this i did it in three pieces i did this piece first and came down the wall and taped it to the wall i then did this piece up and then overlaid this one but when i overlaid it i put more tape in and you should be able to see here what i'm doing is that i'm actually putting a second layer of the butyl tape up there so that when i put this particular one over the top then i've got a double layer they're both sealed together the tapes the the the vapor barriers themselves are sealed together and then over the top of that i go over it with this silver foil tape now it's not a standard silver foil just so you know this is a standard silver foil tape which you you know you can buy everywhere and this is pretty easy to rip or etcetera this is the tape which comes with this particular system and it's a completely different kind of beast and it's really strong okay so we've got a complete system here now the manufacturers who have supplied me with all of this they supplied it all for free they've given me loads of loads of advice on how to do it etc all the way around and you know it's it's a it's a great system um it's one of many different systems which are out there and i'm not tied to these particular people but they've just been really really helpful in the corner here you can see that i've where you're doing penetrations through if you've got pipe work coming through a wall and you go around it with your black tape all the way around the penetration it might be a plug hole it might be any kind of pipes coming through the wall you can seal it the best you can but if it's really difficult to seal it they give you this particular product and here it was i had many many folds so not only did i seal it with all the tight the butyl tapes etc but then over the top of it i went around it with this particular product which really seals it in and if i had a pipe work coming through or cables coming through i could use it here and i'm also told that if you go into a concrete floor or something like that where there might be a lot of dust around you can use this on the dusty floor and make sure that you get a good junction because at the end of the day right it's an air vapor control layer we're trying to control the amount of moisture going through these walls and it's not just the vapor resistance of the material we're using if we got any leakage of any air going through we've got lots of vapor going through with that that's why you cannot go cutting light fittings through this and not sealing it correctly you're better off not to put the light fittings in and i did that on another video in respect to doing a dropped ceiling so hopefully that explains uh how to ins correctly install an air vapor control layer if you need any more information or any help please get back to me speak soon

Channel: Steve Roofer

Views: 90,561

Keywords: vapour barrier, vapor barrier installation, interstitial condensation, roof ventilation, vapour control layer installation, vapour barrier garden room, vapor barrier, cold flat roof, vapour barrier walls, installing vapour barrier on walls, vapour barrier membrane, how to vapour barrier a wall, how to vapour barrier a ceiling, what vapour barrier to use, vapour barrier for cold flat roof, zzzamit, cold flat roof ventilation, warm roof insulation, vapour barrier vs air barrier

Id: zqw0gu4px7Y

Length: 5min 55sec (355 seconds)

Published: Sun Mar 27 2022