On Sep 6, 4:10*pm, grasshopper wrote:
On Sat, 6 Sep 2008 09:40:52 -0700 (PDT), PerryOne

wrote:
On Sep 5, 10:00 pm, grasshopper wrote:
Suppose a house has radiant barrier housewrap, then 1 x 2 furring
strips on the outside and topped with 4 x 8 hardie concrete siding.
Would there be any problem if I installed foil backed fiberglass in
the wall cavity with the foil facing the interior?

Just what exactly is your target?
What are you trying to achieve?

New construction. *Goal is:

Repelling max amount of heat in summer before entry into the interior.
Repelling max amount of heat back into the interior in winter.

The wall studs are 2x6 with R19 fiberglass to impede movement of heat
in any direction. *R19 is the greatest R value I've found so far for
5.5 inch wall cavities. *Do you know of better insulation materials
that will fit into that cavity?

Ceiling will be ~R50 with perforated radiant barrier laid over top.
2x6 floor joists will be insulated but haven't addressed that yet.

Any info or critique would be greatly appreciated.

Spray foam or foamboard at 5.5" can be R 40 with a radiant barrier on
the foamboard