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Best stick frame wall system

elevatorman's picture

In the opinion of the body, what is the best,greenest wall construction technique as it relates to vapor drive. My building will be in the north georgia mountains. I am a firm believer in peel and stick and spray foam insulation.

I can't offering anything in (post #181217, reply #1 of 5)

I can't offering anything in terms of feedback to your questions, but I have a couple of questions from your post.

What is 'peel and stick'? Also, since you are looking at spray-on foam as the insulation of choice (closed or open cell?), why not consider SIP? Recently someone in NE Georgia started manufacturing SIP panels, and someone in TN has been for a while.

There are many good wall (post #181217, reply #2 of 5)

There are many good wall stystems. A wall system that doesn't deal with vapor drive well is, by definition, a bad wall system. So toy can sabotage a good system with bad ideas. Like putting some sort of vapor barrier on both sides of the wall -- peel and stick on the outside and plastic sheeting on the inside, for example.

The best wall systems can dry to the inside, outside, or both.

Peel and stick membrane and spray foam are boyth great products, but they can be used in ways that won't allow a wall to dry. There are some good articles on our partner site, Green Building Advisor. One thing to watch out for: in the southeast, open cell foam seems like a popular choice. Icynene suggests using an interior vapor barrier, otherwise the foam may absorb interior moisture. Be careful with interior vapor barriers as far south as you are. Closed cell foam, on the other hand will qualify as an interior vapor barrier, because it's impermeable to moisture, but it won't cause the problems that a sheet of plastic will.

Here are a few articles you may find useful.

The Perfect Wall, Roof, and Slab by Joe Lstiburek

Humidity, Mold, and Indoor Air Quality

Vapor Retarders and Vapor Barriers

Forget About Vapor Diffusion, Stop the Air Leaks!

Also, the Q&A forum over there is pretty good for complicated building science questions.



Dan Morrison

spray me down (post #181217, reply #3 of 5)


My opinion? spray foam, closed cell only. Zero air infiltration, an air and vapor barrier, no internal convective or radiant transfer. Acoustical and structural benefits. Will keep the place warm in the winter and cool in the summer. 

If I couldn't have cc spray foam, I'd go for dense-packed cells, and probably omit the vapor barrier, though I'm not totally familiar with building in your climate. But I'd consider letting the cells absorb moisture as needed, and dry to the inside or outside as able.

There are 10 kinds of people in this world; those who understand binary and those who do not.

Wall construction (post #181217, reply #4 of 5)

I have built upwards of 60 homes using 4" SIPs. For my money these are the best wall systems manufactured or site stick built money can buy. Spray foam insulation can trap the moisture in green wood and can cause problems.

You do not require alot of construction knowledge to errect - I work with alot of rookie builders and they catch on quick.

SIPs? (post #181217, reply #5 of 5)

SIPs are fine and dandy, but they are not really "stick framing" which is what this poster's question was about.  

"Spray foam insulation can trap the moisture in green wood and can cause problems."  

Then pony up for kiln dried lumber. 

Regardess of KD versus non-KD, spray foam trapping moisture? Ah, never mind.

Best, Mongo  

There are 10 kinds of people in this world; those who understand binary and those who do not.