R-Value of dimensional lumber.

[TCB]

My Dad and I are currently insulating a heated garage we just built. And the
question came up what is the insulation vale of lumber? Basically what we
were wondering, is if the walls are framed with 2x6 with R-19 fiberglass are
the studs between the insulation a better or worse insulator? Also it came
up becuase of headers.

Thanks

[AJ]

Wood is a poor insulator. Your looking at about R-1. Steel framing
would allow almost 100% insulation around the outside. A garage can
not be connected to a homes ventilation system. Most likely due to the
risk of CO poisoning.

AJ

[Matthew S. Whiting]

Wood has an R value or around 1/inch. It varies by specie of wood, some
being better at around 1.25 and some being a little worse. But if you
figure an R of 1/inch you'll be in the ball park. So a 3.5" deep stud
will have an R value of around 4 give or take. This is much less than
the same thickness of fiberglass (11-13) so, yes, the studs are a better
conductor than is the insulation in between the studs.

Matt

[Rico dJour]

>From: "TCB" t...@cmsinter.net

>
>My Dad and I are currently insulating a heated garage we just built. And the
>question came up what is the insulation vale of lumber?

Here's what I use when running energy calculations:

Item R/inch Mat'l Depth R U

2x4 1.25 3.50 4.38 0.23
2x6 1.25 5.50 6.88 0.15
2x8 1.25 7.25 9.06 0.11
2x10 1.25 9.25 11.56 0.09
2x12 1.25 11.25 14.06 0.07

3/4" plywood 1.25 0.75 0.94 1.07
5/8" plywood 1.25 0.63 0.78 1.28
1/2" plywood 1.25 0.50 0.63 1.60

1x subfloor-softwood1.25 0.75 0.94 1.07
1" hardwood 0.90 0.75 0.68 1.48