What type of Insulation can I use on the exterior of my home?
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What type of Insulation can I use on the exterior of my home?
Scott Muller
April 18, 2019Last updated: Aug. 3, 2020
I have an old home, circa 1920’s, I’m currently renovating in Saskatchewan, Canada. I want to add insulation on the exterior of the home. The house is currently covered with an old concrete type stucco that may be original?
我在想一个“气泡包装”类型的产品，捆扎然后壁板。我现在怀疑我自己，因为那是一个蒸汽屏障，可能会在以后的道路上造成问题。外面似乎有太多相互矛盾的信息，让人很难做出决定。Love your work on the site and thanks in advance for any information.
Cheers,
Scott
You were right to second guess yourself, areflective foilon the outside would not serve you well. Yes, it would be avapor barrier, and you don’t want that on the outside. And afoil membranehardly offers any thermal protection at all.
A 1920s home would not have been built with an interiorvapor barrier, but as it likely has multiple coats of oil paint by now it would pretty much have an interior ‘vapor barrier’ anyway, just with a few generations worth of oil paint being applied. What you are likely missing at this point is an effectivethermal barrierandair barrier，所以如果你打算重做外观，这是一个很好的时间做两者。I think you may be best to look into some rigid insulation boards, but be sure to get the right ones, so be sure to read this page first -
The difference between Polyiso, EPS & XPS Foam Insulation & Styrofoam
There are rigid insulation boards that will act as the insulation only, insulation and air barrier only, or all in one - insulation, air barrier and vapor barrier. this is a good and bad thing - we think it's great that they are offered, but I wish I had a nickel for every time I saw the wrong product installed for a particular application and it ends up doing more harm than good.
An insulation like rigid Rockwool (or mineral wool) panels are a safe bet for you as they do not stop the outward migration of moisture. There are two brands that may be available in Saskatchewan, Rockwool (formerly Roxul) and Johns Manville.
另一个你需要的是一个天气屏障/天气抵抗屏障(WRB)，一个可呼吸的屏障会让你尽可能多的水分通过。read more here -
Choosing a house wrap, which is best?
Exactly how much insulation to add is a tough question that only you can really answer, it depends on whether there has ever been any cavity insulation added, how big your budget is, and how much space you have to work with on the outside (meaning - if you have neighbouring homes and setbacks to consider). I hope you could add at least 2 inches, but more is better. Does that help? drop us a line anytime for more details.
因此，我在当地的几家五金店做了更多的调查，并被一家同样拥有住宅建筑部门的商店推荐了Iko EnerAir。然而，我怀疑这个产品会是正确的，因为你建议它往往在你最需要它的时候失败，比如萨斯喀彻温省零下40度的冬天。我是一名住宅领域的熟练木匠，尽管我来自澳大利亚，所以所有关于蒸汽屏障、绝缘等的辩论对我来说都是新的，我在工地上遇到的那些人基本上不知道他们想要达到什么目的，只是和其他人一样做。
Option 1 is the Rockwool ComfortBoard covered in WRB/Tyvek housewrap and strapped or if i used a XPS like Dow Cladmate would a WRB still be required do you think? Am i on the right track?
Thanks
Scott
你是对的，IKO是一个多异氰尿酸酯面板，它的性能下降时，它的冷。这对建筑科学界来说是众所周知的，但当地五金店的员工可能不知道。不仅如此，铝箔还能阻挡蒸汽。
XPS has a nice R value per inch, but again, if you refer to that page on rigid board insulation above you'll see that it's also a vapour barrier. I like your option number 1 the best - I'd be doing Comfortboard since moisture moves right through it no problem.
And sadly it's not a surprise that you are finding very few builders that really understand the properties of the materials they are using, or that there actually are different properties. You are for sure on the right track, and here is a video onbuilding science basicsthat may help you stick to your guns when the old school builders recommend exterior vapour barriers without even realizing it :) And notice - we used Comfortboard.
Hi Mike,
Thanks for the video recommendation, i see myself going down the rabbithole and watching everything you guys have!!
Im going to go with the ComfortBoard method, what do you suggest for fastening the board? Fasten it in conjunction with the strapping or fasten the board first then the strapping after? If you have any tips or recommendations on the install id love to hear them.
Thanks
Scott
Hey Scott, I'm glad some of those videos are of value! I would use the strapping to fasten it, Rockwool boards won't hold so well with just screws. If you watched that siding install video you'll see we did two layers of it but the principle is the same. In a perfect world you would have the Comfortboard then weather barrier both attached with the strapping. Dont forget to overlap and tape the weather barrier.
You need to make sure the bottom course of Comfortboard stays in place and supports the others, so it would need some screws if it isn't resting on something like ours is in that video, but the upper courses of Comfortboard won't need a lot of screws before siding. Screws cost money and they do act as a thermal bridge, it's not the end of the world but don't overload it with them for no reason. A certain amount of perforations in the weather barrier are unavoidable, but if you put any gaping holes in it be sure to tape them up to prevent air leakage. Glad to be of help.