Radiant Barrier / Building Wrap
February 20, 2012 § Leave a comment
The part I am really excited about that I have eluded to before!! 🙂 So, a few months ago at a lecture I randomly met Jason Woodbury and got the chance to talk to him a little bit about his products. He reps a lot of different projects (http://keyenergyid.com/) but I want to talk about the radiant barrier, I think it’s simply a fantastic idea for a tiny house! Jason was kind enough to come check out my build this past weekend and talk about options and uses for the barriers. After meeting with him again I am even more sold that it’s going to be great, particularly for my project, here’s why!
This is the first product Jason showed me which is simply a perforated radiant barrier, he tends to use these in a lot of attic spaces and crawlspaces where you want the breathability but it still reflects heat back inside the house as well as keeping the harsh suns rays out. While this would be great for a tiny house I am not sure I could justify the material costs with the payback for simply the radiant aspect. The solution, a non-perforated versions! This acts both as a vapor barrier and an air barrier if sealed correctly AND you get the benefits of the radiant barrier. I haven’t directly compared the cost of the barrier with that of say, Tyvek but I should, and when I do I’ll post it :).
The second material is a foam filled version of the first, if you will, it’s foam sandwiched between two layers of the reflective material. It is about 3/16” thick (ish) and is not perforated. It can therefore act as a vapor/water and radiant barrier as well. Since its foam in the middle it’s even self sealing when you nail through it. Not only that, it adds to the insulation value when combined with an airspace! Up to an R-16 I believe (measured in the up and down direction, if it were added in a vertical direction, i.e. walls, it would add about an R-6 when combined with an air space). I feel like this is going to be VERY important for me in my floor particularly because of my radiant heat floor system. I would like to have my energy being used in my tiny house rather than it radiating its way out through the bottom. As some of you know I am putting in R-36 insulation in my floor and this will boost that up to approximately R-42ish. Nuts! I also know some of you think that is a lot, but I live in Idaho, it does get cold here in the winter, it is definitely not unheard of to have an r-value that high :). I think it would be awesome in my walls also but when you really look at value added/price cost it seems to me to make a little more sense to go with the non-perforated vapor/air/radiant wrap.
There is a third product that is similar to the second but it is a plastic bubble wrap (looking) filling instead of foam. This material is virtually the same as the foam filled as I understand.
And Tobi is being so helpful as always