Understanding Air and Vapor Barriers INSIDE your House

In this episode of the Build Show sponsored by Siga we are discussing vapor barriers. When and where do you need them, how to install them, AND the importance of air sealing on the inside of your house especially in cold climates. Big thanks to SIGA for flying us to Switzerland and giving us a fantastic tour of local job sites plus their beautiful factory. Impressive company!
BIG Thanks to SIGA for hosting us. www.siga.swiss/us_en/
A TON of Behind the Scenes - / risingerbuild
/ thebuildshow
More reading on this topic:
Controlling Moisture in Mixed Climates by Joe Ltiburek and Joe Carmody
Avoiding Wet Roofs (parts 1 and 2) by Peter Yost
www.jlconline.com/how-to/insu...
Avoiding Wet Walls by Clayton DeKorne
A One-Way Vapor Barrier? by Ted Cushman
The Last Word (We Hope) on Vapor Barriers by JLC Staff
Huge thanks to our Show sponsors Polywall, Huber, Dorken Delta, Prosoco, & Rockwool for helping to make these videos possible! These are all trusted companies that Matt has worked with for years and trusts their products in the homes he builds.
www.Poly-Wall.com
www.Dorken.com
www.Huberwood.com
www.Prosoco.com
www.Rockwool.com

[@davemastriano2181]

I'm a licensed engineer/construction manager in FL and have recently chastised a contractor on a $20M project for showing me design details where they would install a vapor barrier on the inside of insulation in climate zone 1. I explained it to multiple designers on the contractor's side this is not how we build down here (they were from NC). I literally had 3 conversations and they still didn't understand, so I eventually had to direct them to remove the damn barrier altogether. I watch Matt's videos often so it came to me, I bet he has a good video on it and I'll send it to them! Love your stuff man, keep up the good work!

[@raybrensike42]

Back in the 70's when I began as a carpenter, we would staple 4 mil poly on the framing, after the insulation was installed, for our vapor barrier. (install vapor barrier on the warm side) The boss wanted it over all the windows. It was not at that time cut out around the windows. Then when the sheetrock was installed, you could see how the outside air pushed against the poly as it tried to infiltrate the house at the windows. I was amazed at how much pressure was there. It would bulge out the plastic sheeting several inches in toward the room. When you pushed on it with your hand, it was like pushing on baloon. Lots of air infiltration happening, but the plastic sheeting on the warm side was not placed there for preventing air infiltration. It was there to prevent warm moist air from cooling off as it moved toward the outside, and reaching it's dew point and condensing inside the wall. We were not using any house wrap on the outside of the wall at the time. I wonder how much that would have helped, but I was amazed at how air was trying to infiltrate to the inside of the house and not the other way around. We had installed the windows directly onto the plywood sheathing, using the window flange and nailing through that. They were wood clad (with plastic) windows. Perhaps there was a lot of infiltration happening at that joint, between the window flange and the sheathing. I'm sure some of the air came through the weatherstrip of the windows also. They were casement windows. Sometimes we had trouble insulating in corners, such as on a hip roof, where it isn't so easy to get as much insulation in, and sometimes on a cold day there would be frost seen on the sheetrock in the corner, if the insulation installation wasn't properly done there.

[@rickwest2818]

This is a complex topic that is full of many different opinions. Add to that the variances in climate across the country and it gets really complex. I'm also of the opinion that many builders don't really think about these things.

[@indusrtial]

Matt, I just recently discovered your channel and first of all I want to tell you thank you. Thank you for bringing all sides of home construction to the forefront for us to understand the correct science. A little background, after getting married we moved to a brand spanking new home in Southern Oregon around 2015 that my parents had bought, I realized how poorly it was built immediately. If you turned off the AC within 30 minutes it was the temperature of the outside and it took a bit before you could bring the temp back down. We decided to buy a home of our own after that, but were disappointed to find similar build quality throughout, so we bought a 115 year old home. Thanks to you I've done major improvements to our home were the AC does not have to be turned on until 3pm when it's in the 90's outside. Being a total engineering and learning nerd this is fascinating to me. Thank you again.

[@buildshow]

Love hearing this! Thanks

[@johnpgellatly]

Fifteen years of attending ASHRAE meetings, first time I have ever watched a simple explanation of vapour barriers. Really appreciate your work, Matt, keep it up. You and Joseph Lstiburek are my building science heroes! Would appreciate you addressing the comments about drywall screws, related, liked the video about foaming electrical boxes properly that you did recently, need something like that for the other penetrations that we all make.

[@Mattstafford2009]

My previous understanding (potentially mistaken) is that yes it would be best to somehow be able to not have any penetrations onto the vapor barrier but you can't have everything be perfect so having a vapor barrier up still stops 98% of all the moisture that diffuses through the drywall than not having a moisture barrier, as the job of the moisture barrier is to stop diffusion through the actual drywall cells NOT holes in the drywall from nails or screws. The drywall screws/ nails I'm assuming is supposed to be sealed via joint compound/ paint and would just diffuse moisture as if that small section didn't have a moisture barrier, so yeah an 4X8 sheet will have maybe 20 screws or something but that only adds up to just 5 sq in. of non-moisture barrier drywall but the rest of the 32 sq ft has moisture barriered drywall.

[@brainfreeze1925]

An eye opening video. Thanks.

[@j.n.572]

Just as important, you have to stop cold air from hitting the vapor barrier. I have seen countless times where 6 mil vapor barrier fails because of poor insulation allowing cold air into the wall cavities. In effect, this turns your beautiful vapor barrier into the condensing surface and creating a lake between the vapor barrier and the drywall. I've seen this happen to the point where the drywall started to fall apart mere months after installation on a brand new building.

[@szargos]

Cool to know about these type of new products that Siga has. The problem where I live in the states though, is not in the products, its in getting the installers to do a proper install. The only way this would work for me would be to do it myself.

[@Natedoc808]

Since finding your channel I have really viewed how to build a home properly extremely differently than I did before. Thanks.

[@thecat6062]

Well done! It's great that you are out there seeing the different ways people are building structures and expanding your ( and our) knowledge. All too often people get complacent and just stick to the same old same old mentality. Nice that you are a very forward thinker.. nice for us too. Thanks!

[@joea1433]

Your videos are vitally important because of the huge amount of new people in construction and because, historically, no one cared much about these details. I worked as a building inspector and it was extremely difficult to get compliance because they were really not ready for prime time.

[@isakaldazwulfazizsunus7564]

They're used to working one way and it's worked perfectly so far. The only thing is, requirements change over time and as windows and energy efficiency requirements evolve, techniques have to change as well. I have it from a tradesman that Velux windows are still being installed improperly because pieces designed to avoid air leakage around the corners aren't used because the professionals placing them don't know what they're for.

[@SamWalston]

I was impressed by the teaching technique, the background, the ease of teaching, the pushing away of the paper displays, the entrance of the water bottles,... I was wondering how many takes it took to get this right, it would be neat to see a little blooper reel. Great teaching job

[@saywater]

Thanks for mentioning the Canadians viewers. We loved your show. It is so helpful and unique. we really appreciate your work. Your faithful Canadian fans.

[@jonathansturm4163]

Tasmanian viewer here :-)

[@wattyboy87]

Just started using SIGA products on a home in Toronto, ON Canada. They had a rep come out to show us how to use the product as well which was very helpful. I'm sure we'll be seeing more of it in the future. Thumbs up!

[@Salanan]

Thank you for this, just recently started watching your videos as a home owner, and you keep talking about these barriers and i didnt really understand it before.

[@ArneJohanssonMpls]

ON The BUILD SHOOWWWWWW!!!!! Awesome video!! Heck yeah, love the vapor barrier, that product looks cool.

[@KplusU]

This is where you shine Matt! This was a great video!

[@quinnkent3558]

Thank you Matt. This is great content!

[@Prowlerook]

Just bought a tiny little home with issues that need to be fixed, this was outstanding!! Thank you so much!

[@georgelewisray]

SIGA:: enjoyed learning about them and getting educated in the process.

[@brybino]

Love the whiteboard stuff!

[@amandabruney3835]

Excellent video! Patrick thank you so much for the information.

[@irondiver292]

Very well presented. Also amazing company and representative.

[@kylemacht]

Awesome instructional video, keep them coming!

[@MegsCarpentry-lovedogs]

Reflective on these older video's when it was before Covid in 2020! Gosh! Then building materials and chain supply and labour issues! Now in 2023 life is slowly getting to some normalizy....but with a recession allegedly....building material costs here in Atlantic Canada are considerably lower compared to in the pandemic! Crazy pricing during the pandemic! Thank you Matt and team for all your videos to help us along🙏 🇨🇦🍁

[@AngelTorres-tk2nw]

Wow, I am a C10 contractor, Matt Risinger is from the future, a lot of learning from his instructional videos. Thanks Matt.

[@flinch622]

As an aside, conserving energy for the Swiss is a very big deal. Except for a handful of countries with north sea access [and I think Italy], nobody has oil. For that reason, market forces will have them leading the world in energy conservation - just discard the climate change nonsense injected by the politicians and follow the science. Getting Macron'd never solved a single problem.

[@tammoilliet8683]

I appreciate the mention of us Canadians. I as well as many other Canadian's appreciate your show, especially when it comes to insulation and vapour control. You go Matt!!

[@williamarmstrong7199]

And correct spelling too! Being dyslexic spelling a burden to me so when people deliberately spell things wrong it really pisses me off. Colour and Vapour its not hard even for me. Mind you hearing Americans slaughter the word "Solder" and pronouncing it "Soder" is another pet hate :) its pronounced Sold..er for those needing to know.

[@PxssyGalore]

@@williamarmstrong7199 and caulking, not cocking..lol

[@JackStraw1990]

Maybe basic/obvious for some but for me starting out in the building trade as a carpenter and builder this is super helpful! Thanks!

[@firstreviewer8966]

Different stages, not only in construction, but also of importance. Understanding the long term savings as to the initial cost differences, which includes the a comfort factor will go a long way in determining which direction to take. Just a Great Video! FR

[@johnbazemore9985]

Disappointed in this infomercial, Matt! First time I didn't have one word written on my notepad from your show.

[@irondiver292]

John Bazemore I think it’s more of a Bread crumb to encourage you to research the system

[@johnbazemore9985]

@@irondiver292, though I believe I understand your reply and cannot completely disagree, I must ask; if Matt intended to encourage fans to research the system, (which is the definition and purpose of a 30 sec. commercial), why is Sig only appearing in the description and not in the title, giving the initial impression this was educational with scientific research on a particular subject rather than a particular product. What has a paid spokesperson that's usually considered sincere and unbiased in his seemingly normal atmosphere quickly abandoning the misleading, "attention grabber," hoping to appear as usual while fulfilling a contractual agreement to sell a product? (hint) Older brother to the 30 second commercial that leaves breadcrumbs to 16mins. of usually grossly exaggerated and questionable .....I have severally digressed. Though the answer is Infomercial, I understand making a few extra dollars, Matt, but the Texas accent plus the honest demeanor is your meal ticket.

[@chrishayes8197]

it looks to me like the spot Matt was stuck in, and maybe could have navigated differently, was to discuss the need and benefit of having a vapor (and air) barrier, and show Siga's product as a good solution, without just parroting Siga's sales brochure about that product. Specifically, WHY does it matter if a vapor barrier is "one-way", what does "one-way" mean? Paraphrasing Siga's talking points on this would have been better than the too-brief mention those points got. The diagram of water/heat/air/thermal doesn't address this clearly enough for folks who are not already familiar with them. (okay, now that we're all done beating up on Matt, let's hope he does a follow-up video with a detailed on-site install of Majrex here in North America)

[@wandag1493]

They flew him to Sweden and they have a product and sales model that's worth knowing about. The emphasis on correct installation and not just product specifications was refreshing. If you stuck around feeling an annoyed by the commercial relationship, that's more on you than the host.

[@yanik.ottenbreit]

Amazing! You're going to hit that 1M by April 30 I bet. Building season BEGINS.

[@civildk9077]

Personally, I love the European theory regarding the lifespan of buildings (generations!) and the 'functionality', i.e. 3 pt. windows and 'Rolladen' window covers.

[@markduddy100]

Great really informative, I am going to watch more sessions as I am interested in building a cabin in Flagstaff Arizona with my son!

[@bumblebeeelle]

I love the drumbeats that follow right after he says "on the buildshow" :) very smooth transition

[@adrojas2003]

Hi Matt, just turned into your channel. Thanks for all the good information, and your presentations are world class! Glad to find you.

[@num1ghop]

Hey Matt. Great stuff here. I saw your video about vapor barriers that you made in 2018 and it says that you basically don't need one. This one seems to say the opposite. I was leaning more towards not doing one. I live in the PNW which is mostly a heated climate (meaning I'm using heat more than cooling), but it isn't super cold here either. I am remodeling my upstairs bedroom. This is basically an attic turned into a bedroom with two sides still having attic space (where the rafters run down) The house is 1926 and the rafters (which are only 2x4s) meet at the peak with no horizontal supports. Basically like your new attic build in your home but without the horizontal supports on top about a foot down from the peak. I'm going to be using all the space so ceiling will be on the rafters. I'm using spray foam and then for the ceiling I wanted to use wood planks or some kind of wood faux backer board. If I'm using spray foam on the ceiling I know I need to seal the room as best I can. I was wondering if I used the wood planks do I need to seal every crack kind of like drywall would do? If I use the faux wood sheets can I just paint the back of them? I'm just not sure if I need to seal inside the spray foam.

[@kentaltobelli1840]

My interpretation is that this material serves first and foremost as an air barrier and that the vapor permeability has a marginal impact. I wish Matt had actually explained the usefulness of this directional vapor flow.

[@ecospider5]

I really don’t understand why people make vapor issues so hard when explaining it. If you use a 6” wall with fiberglass insulation as an example. You want to keep the water vapor out of that 6” of fiberglass. Warm air and holes in the warm side of the wall can carry moisture into that fiberglass. The goal of the 6 inchs of fiberglass insulation in the exterior wall in cold climates is that entire 6 inch area stays closer to the interior temp than the exterior temp. So if the air inside that 6” of fiberglass hits a vapor barrier against the exterior plywood in a cold climate you have warm wet air hitting a cold surface causing condensation. When that condensation overwhelms the wall framing you get mold inside the wall. If you put a vapor barrier on the inside next to the drywall then the air in that 6” area of fiberglass insulation will be warm and DRY. When that warm dry air hits the cold outside plywood there will be no condensation. So no mold. This is reversed in the hot climates when the cold is on the inside of your house and the hot is outside. You will get condensation on the drywall side unless you stop the vapor before it enters the 6” fiberglass insulation. In this video he was explaining how much holes in the wall can carry water vapor so that should also be delt with. But he did not describe how to do that. Maybe the material being installed behind him was supposed to help with that. Who know he never said.

[@clemsontastic]

Great summary, thanks

[@matthewbarbour2064]

So what do we do when we live in a climate that features 30.C summers and -10.C winters?

[@4philipp]

Nice summary. I would hope there is some self sealing take that can be put over the vapor barrier over the studs. Then the nails holding up the drywall won’t cause leakage. Just my idea.

[@kennethwallace5168]

I put plastic over my 6 inch walls and noticed water vapor on the sun hit walls on the plastic before I drywalled...this scared me. I felt that is too much water to be trapped in that cavity...I took the plastic off the walls that were hit by direct sunlight...I feel that a wall needs to breath a little, especially when it is subject to drastic changes like sunlight heat. The building materials will store some moister and give it up as well. I felt trapping large amounts of water was a bad idea. So I have not had any problems and the house is now 23 years old.

[@unchannelbyryan]

Problem with this is I live in NC. Hot humid summers and cold winters. You just can’t win. I just made mine as air tight as possible, have insulation installed properly and control for internal moisture the best I can. Hind sight being 20/20 my next house I’m going with closed cell spray foam. Air seal, vapor seal and expansive to prevent gaps.

[@sustainf]

Thank you Matt! Another excellent video! :)

[@mattmuraski]

How about a video for existing homeowners and tips and tricks to airproof/vapro proof their house short of removing all interior drywall and exterior siding?

[@timcora1]

The other (5th?) major element a house needs to control is inbound solar radiation. Letting it in in cold regions/seasons, keeping it out in hot regions/seasons. This could be its own episode (specialised glazing on north vs south facing windows, overhangs, building orientation, thermal mass, etc.).

[@ZimorKilled]

I like it - Solar. Could put this in Thermal? I would also add Insect Control. Matt has a good video on controlling insects with BoraCare.

[@kentaltobelli1840]

@@ZimorKilled thermal might actually be too general now that you mention it, air barriers manage convection, insulation manages conduction, and now we're taking about shading and coatings to manage radiation gain/loss. I like this train of thought

[@ihavefaithnlove]

I truly appreciate this video... I now know I want a "passive house"

[@flynnjp19]

This is a great video Matt, thanks!

[@houtslager]

Your Swiss / German tour videos were just in time, as I and a collegue went to the Dutch Build Show, there I met the Dutch Rep of SIGA and ordered some of their membranes and tapes for a small job in amsterdam, here's hoping it does what it says on the tin :D

[@michellekuo2085]

I am so glad I watched your clip today. The informatipm is so helpful. Thank you very much！

[@CheriBenIesau]

Every show I watch I end up adding another idea to my next house-build. Thank you, Matt, for all the inspiration.

[@TRYtoHELPyou]

i love this show!

[@MRosati5000]

Great tour Matt and Siga from Philly.

[@lalasonycierny1945]

Perfect again!

[@PuerinTheHunter]

@12:53 that is a cool picture!

[@lauraholmes9353]

Haha his subconscious knew he was going to misspell vapour anyway. 😄

[@coryshook7648]

Thinking of building small compartmentalized toilet closet and shower closet, (for lack of terminology), well ventilated of course. Seems like a great product for these locations. It’s all about air control! Deliberate directional movement.

[@spegzly87]

Great breakdown....one comment... I'm sure people are annoyed at the pedantic nature of this comment but I think it's important that we stop saying "heat rises" when really "warm air rises". Heat doesn't care where it goes as long as it's from hot to cold. This and that we put more insulation into roofs (because there is space) makes people forget that there are other important elements of a house that insulation matters just as much in because they incorrectly believe that heat rises.

[@golfmaniac]

Not annoyed at all, its spot on. It is hard to get people to grasp this. Some never do.

[@BryanUhler]

I've heard it said that hot air floats. I like that phrase.

[@paulmaxwell8851]

Thank you! It makes me crazy when people say that 'heat rises'. My framed wood floors are insulated to R36, with perimeter insulation to boot. The infloor heating system? We never use it. The floors are always warm and a wood stove heats the house. Visitors ask me "Why did you waste all that money on insulation? Heat rises!"

[@anonymous.youtuber]

Very nice explanation! Thanks a lot!

[@bikeninja956]

I've researched this and it's probably one of the most inconsistent area's of building in terms of whether it's required or not. Sadly, I still don't know what to do.

[@Cyril8204]

Actually it's very straight forward. If you insulation can not breath to the outside air, you need one.

[@anthonyrochon3907]

What about if you have 2" of exterior foam board below grade? Where will the water condense?

[@ecospider5]

a vapor barrier needs to be in a different location for hot vs cold climates. So there is no single answer.

[@shoyrushoyru]

@@ecospider5 problem is a lot of people are in places that have 90 degree high humidity summers and 20 degree snowy winters all in the same spot. "hot climate" and "cold climate" are two extremes that dont represent the gray area inbetween

[@jwonz2054]

@@shoyrushoyru Exactly, so what is the answer for a climate with hot humid summers and cold wet winters?

[@tscotts9699]

Thanks for the great vids ya big dork.

[@scotthixson5917]

Awesome and informative for Americans who haven’t realized that integrity contracting /building also exist outside of our country. Great new content Matt. I really enjoyed that as a long-time follower of you.

[@buildshow]

Thanks Scott. Much appreciated!

[@davepane7306]

More like "Air tight - endless fight". Air tightness is okay if you live in an RV that you plan on scrapping in 20 years. But the problem with this general philosophy in house construction is that the more the builder tries to control the elements, the more educated the residents NEED to be... BUT... This falls apart as soon as you hand the keys to the owner, especially as the years progress and new residents take shelter. There will be exaggerated issues when a DIYer does a small project, or a resident fails to maintain certain elements, or if they do certain kinds of replacements or upgrades. Not to mention that most people won't know that they need to periodically introduce fresh air into the house. Nobody is going to want to open a window in January. Also as soon as the wind exceeds maybe 20 mph it will cause breaks in the seals (because most builders are not using the super expensive extremely strong tape), these breaks will happen in places that are very unfavorable, leading to more mold than there would be if the tightness & excessive amount of seals didn't exist in the first place. The better thing we should be working on is lowering energy costs and better thermal resistance into and out of the structure. The rest we should leave to the smart basics, like good weather barriers, good thermal resistance, condensation prevention in particular areas, and smart water-shedding and air flow through certain areas.

[@rafaelbravo3623]

On the build showww!!!

[@salomonrod]

Thanks Matt I appreciate your expertise and videos hopefully one day I will meet you in person.

[@jeffmoore2351]

You forgot your Aussie viewers. All good. Like your Build show trying to apply it to Solid Brick wall house built-in the 50,s. Jeff

[@haslerhomesltd]

Awesome episode, Matt!

[@richardjohnson5441]

Great Video Matt.you have a British viewer as well.I actually live and work in the French speaking part of Switzerland in construction,I am a bricklayer by trade but do not get to do so much of that here in CH, It would be a good video explaining how a cavity wall super structure on a UK home performs,I’m not sure if you have masonry cavity walls in the US or they are solid.but the British can not seem to get away from them.while the rest of the world moves on. Anyway super informative series,thanks

[@thedavesofourlives1]

LOL love the low-fi production - Slide off the charts, wheel in the bottles, hahaha would be interesting to see that kind of stuff emphasized in the post production.

[@adobemastr]

Those robots beginning at 9:20 are incredible!

[@fredA1234]

So my question to you is. I had a 10 x 20 shed build so I could use it as an office they put pressure-treated plywood then put the 2x8 on top and then a mildew resistant outdoor subfloor on top and then build the shed, insulated the floor, but did not use a vapor barrier. Do I need one and if so, what do I do now I was thinking of putting ice and water shield on plywood. Would that help? Thanks Fred Ps I live in New England and I’m using a mini split for heat and AC. And using spray foam for the walls and ceiling, if that makes a difference.

[@tulsapete]

How do you handle a installing vapor barrier in a renovation (down to the studs) without making it cost prohibitive by removing all cladding on a house that has 1950s fiberboard sheathing? Just install closed cell spray foam in the wall cavity?

[@garrimic3]

Is the diffusion calculation based upon painted drywall or unprotected drywall. I do understand that a hole in the wall doesn’t matter, but calculations should be dramatically different between painted and unpainted drywall.

[@wags99999]

Incredible information, you do the industry proud. Thanks

[@DirkDelfortrie]

Excellent info and content 👍

[@vikentijslauruts2153]

Top notch. Love it Want to go to the academy

[@joshtargo6834]

Well done Matt.

[@cfamily9419]

16 mins and no answers LOL! Just a high level explanation of the importance of having a barrier. It was mostly an advertisement for SIGA

[@0714will]

😆

[@MP-zv6fm]

Hey Matt, if the roof sheathing has vapor barrier, and insulated with a 1.5 inch comfortboard 80. Eliminating the air gap and installing the metal roofing directly onto the Rockwool should not allow for vapor or moisture build up since the comfortboard should stop the radiant transmission into the roof interior or vice versa during the winter with the heat transferring out through the sheathing through the rockwool and onto the metal roofing.

[@WilliamVallance]

I would love to know what steps one should take to improving my 1900 home in the north. Preferably without tearing up the pastor walls.

[@FreeRange1234]

Looks like the German could pinch your head off. :) Great video. Thanks Matt for all you do.

[@danielclarkearchitect]

Beautiful explanations!

[@369.0]

Hi Matt, Great demos, thanks! QUESTION: I'm planning a whole house renovation (my house is about 27 yrs old and was built fairly well) I am planning on using as many of your recommendations (improvements) as I can. Can you point me to "the right way to finish a basement"? (waterproofing, vapour barriers, insulation, THE FLOOR, etc.) thanks!

[@hellonoko]

Start at buildingscience.com :)

[@stevecotes301]

As hellonko pointed out buildingscience.com is a great start. But also, what do you have and what do you want? Are you on a well-drained slope with no water problems, or is the basement catching water and you need to worry about infiltration and maybe adding a drain? Is it a "day-light" basement with some venting easily available, or fully buried under another story? Do you want an open recreation area, with good air flow, ect. Or, are you intending to have a kitchen and/or bathroom in the space which can add lots of moisture. Don't be afraid of engaging a professional to talk through your plans and ideas, you might get it for free, but a few hundred or a couple thousand dollars (depending on the project) of guidance and advice might get you something you're much happier with and save you money in the end.

[@jamesbramlett5407]

Helluva Preso, Matt!!

[@smartchip]

Good video, epic in my opinion, thanks,

[@deanwells2859]

I second what a prior viewer said. We can all see the product that was installed, presumably directly against the roof joists. What is the ideal goal any home builder should have when we address the space under the roof deck in terms of permeability of moisture? Is it realistic to presume that the number should be zero? Starting directly under the roof deck where we are going to insulate under the deck, should we put the vapor barrier up against the deck, then our insulation or should it be the reverse? I have also heard guys saying it is important to have passive air movement going from the eaves to a venting cap on the roof to help remove the heat buildup in the “attic”. I am not trying to add more complexities to the equation, I just really want to learn what are the best practices to have a sealed home environment where we are able to minimize the energy usage to keep the home very comfortable. I may be looking at building at least two different homes in different climate zones around our country. I am willing to make the initial investment so that they will still be standing generations beyond my life and still be well above code.

[@user-cw1rb4tz5i]

Love your content! I would like to know if you could do a video on how to retrofit insulation on the outside of drywall by creating a space with one by fours or something like that? And then cover with some sort of shiplap. I was curious if we could lay some sort of barrier layer like to talk about in this video and then possibly insulation board and then put shiplap over top of that. I am doing this in a house that was built in 1983 that has very poor or minimal insulation throughout. You can basically hear conversations everything through the walls if you’re standing outside the home. If a family is talking even a little bit louder than normal you can hear the conversation. The siding on the outside of the home is cedar board with some sort of insulation board underneath it, I believe it’s quite thin, then 2 x 4 construction.

[@cliffp.8396]

Excellent tutorial

[@tagarden]

I have never seen anyone explain what happens to that beautiful vapor barrier when you put several hundred drywall screws through it.

[@MrRobertHarding]

not to mention the hundreds of thousands of staples used to fasten it which will 99 times out of 100 not be taped over.

[@chrishayes8197]

is it 100% tight? nope. Is it 99% better than no barrier? yup

[@igarasjen1128]

Those screws and staples are of no consern

[@danielfronc4304]

@@hosmerhomeboy Can you not use vapor barrier with tape AND use the acouticseal as well? I am not at all familiar with acousticseal. I am a novice in terms of building but have done a little bit of everything over my many years. I am planning on either re-habbing an old victorian home with high ceilings out in the mid-west to retire to or have the framework of one built which I could then finish. I hope to act as my own contractor, studying up on all code requirements. Electrical I would leave to the pro's as well as the basic plumbing. I know building codes can constitute a book the thickness of a bible but am planning ahead and have time.

[@OttawaMikes]

The screws seal the hole. Barrier integrity is maintained.

[@j.o.a.t9718]

Thanks for the Canadian plug.

[@dunlaoghaire1000]

Big thanks!

[@ChrisMaveric]

Excellent video.

[@gsanning]

Thanks again for producing these videos. So If you live in a climate where there are both cold winters and hot humid summers, you would put some sort of vapor barrier on both the internal and external sides of the walls?

[@dallasdandy6276]

Did you ever get an answer? A question I have been trying to get an answer to too but no one seems to ever want to answer the 50/50 climate question. My conclusion now since I'm insulting my attic is to put insulation with barrier facing down in rooms which will or would produce too much humidity e.g bathroom & kitchen and have face up on rooms that are directly getting the best of the sun heat but less humidity.

[@jamespayne9217]

Another great video! Thank you. Also I am wondering does Rammed Earth building need a vapour barrier?? Cheers

[@meceiza5575]

Thank you for the video! So…If I have a framed structure with a crawl space, closed cell, Tyvek on the exterior, Rockwell Insulation, and using T&G bead board for my interior walls, do I need a vapor barrier on the inside? I’m about to install the insulation and I’m not sure…Thanks in advance!!

[@dentist2112]

I would like to know your thoughts on sigas tape vs hubers tape. Do you see yourself using similar materials from Europe over the us made materials in the future?

[@johansteyn3756]

If I use cement board, won't something like latex (tile bond) used in waterproofing tile grout also work on it? I have built a koi pond using it on concrete and it worked great. I mixed 50%/50% cement /sand with tile bond and used it like a sludge.

[@Hailexx]

Loved the style of this video, and all your latest videos out of Switzerland. Inspiring and well shot, cheers to many more Matt!

[@mWaffen]

Outstanding

[@tahoe6182]

Is it good too close up the outer wall of a lifted house like the bottom outer walls from air blowing under neath the house i sprayed foamed it already

[@1ronhall]

Matt, great video, but what’s the solution for existing construction? I like to improve my house structure.

[@bobsmmrs8712]

In your intro I thought Sigo was going to have a Gortex-like fabric affordable for vapor barriers? I’ve priced using LL Bean jackets and it doesn’t work. Is this anyone’s goal? Moisture goin out but not in sounds ideal.

[@rogernemos795]

A Great THANK YOU!

[@12danherron]

Hello Matt!! Any thoughts on "swamp" coolers and how to manage vapor? Desert dweller respects your opinion

[@DanielinLaTuna]

Dan Herron, hopefully Matt will reply. Meanwhile, here’s a little desert advice. Swamp coolers won’t work during the “Monsoon” season - for those few weeks a mini-split system is effective and not expensive. For the rest of the hot season the swamp cooler is ideal. Your desert air is dry enough to absorb and remove the moisture. And a somewhat “leaky” house works in your favor. I don’t think you get terribly cold in the winter, so running the mini-split as a heat pump in winter can help with heating. If you’re building a new house (and remember, Matt is in hot/humid Texas, not a desert) and want to insulate to the same degree that Matt does, a swamp cooler is a no-no

[@buckshot70737]

Thank you Matt. This is a great video explanation of not only products but also the role of water, vapor, and air

[@maxpyane9918]

Hi Matt this might be out of your area of expertise but I was wondering if you knew what is the best way to apply insulation and vapor barrier to a van for the purposes of a mobile home????