[Greenbuilding] Foam installed between framing during framing

[Frank Tettemer]

While Building "Science" uses exacting figures, and also really know 
their stuff,
my take on Building "Construction" says Ixnay with the precut EPS 
squeezed between truss top cords.

My reasoning for this statement is around the huge amount of 
opportunities for leaks, due to:
possible inaccuracy in cutting the EPS.
fitting the EPS around the metal truss plates holding all the cords 
together.
the inevitable wood movement, (designed in by Mother Nature), of the 
truss members,
as well as the fact that most top chord members of commercially 
constructed trusses are 2"x3" or 2"x4" in width, which is not very much 
thickness for the EPS insulation, as far as R-value is concerned.
It is my take on it that trying to make a conditioned and useful space 
out of an attic has more problems associated than there are solutions.
However, I could be wrong about this.

Frank Tettemer
...........................................................................................

Eli Talking:
I am wondering if it would be reasonable to install accurately precut 
eps foam between joist, rafters, or top chord of truss during the 
framing to achieve a cheap relatively tight installation when compared 
to fiberglass with the air seal being achieve outside the framing with 
continuous 6” eps foam managed for air tightness. More detailed 
description is below.

-- 
Frank Tettemer
Living Sol ~ Building and Design
www.livingsol.com
613 756 3884