2007-04-25 02:46:41 · 2 answers · asked by Kimberly K 1 in Home & Garden ➔ Do It Yourself (DIY)
The R-Value of Type I, Expanded Polystyrene Foam that meets ASTM C – 578, calculated per ASHRAE published values at 3.85 per inch at 75° F, 4.19 at 40° F and 4.35 at 25°.
So say 3.5"xR4=R14
Solid foam panel 3.5" [Dow] should give you a R-value of 17.5
http://www.dow.com/styrofoam/na/agtherm/prod/scoreboard.htm
Read here: http://www.universalfoamtech.com/Sips-Homes-Case-Studies.htm
http://users.chartertn.net/dhrivnak/sip's.htm
2007-04-25 08:12:33 · answer #1 · answered by Anonymous · 3⤊ 0⤋
The link will pretty much explain R values, and various insulation materials. R values are othen mythical as advertised, depending on the substance. In your case Cellular foam offers 4.0 per inch of thickness. In North America 12.0 to 15.0 is acceptable for walls, but certainly industry standards help dictate that. R 19 or higher will offer minimal difference in walls, and perhaps not actually fit between studs and interior walls to go higher, as in R 30 or better in an attic.
http://www.rvalue.net/
Steven Wolf
2007-04-25 03:24:21 · answer #2 · answered by DIY Doc 7 · 0⤊ 6⤋