Exterior foam sheathing video - 4"!

[John Raabe]

There are two videos here (the second will run after the first) where a careful builder shows the techniques he has developed to do airtight exterior foam insulation. This makes for a superinsulated 2x6 wall with 4" of foam board on the outside.

http://www.greenbuildingadvisor.com/how-install-rigid-foam-insulation-outside-house

[bayview]

   Wow!  R-40. . . I wonder whats in the ceiling.  How long does it takes for the payback?  (Cost - Energy Saved)

   Quite a drip cap. . . They must use some long nails for siding. (?)


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[poppy]

Thanks for the videos John.  It relates to my plans for insulating the cabin walls and roof.

The video doesn't mention what the climate is where they are building, but if it is a cold climate, I don't understand the use of foil faced insulation facing out.  That would make sense in a hot climate.

Correct me if I'm wrong, but aren't superinsulated houses usually more practical in cold climates?

[twize]

This technique is becoming more popular in Alaska, usually with just 1" of foam though.  We're putting 2" of EPS on the outside of our 2x6 wall with R21 batts inside the stud bays, then 1 1/2" foam sandwiched between the studs and drywall using 2x2 horizontal strapping to eliminate puncturing the vapor barrier with electrical boxes.  The always rising heating costs make this pennies in a bucket for R35 walls.

Tim