R-Values of Common Building Materials!
The R-value of a material determines how quickly heat is conducted across it. The values below are some of the more common R-factors for surfaces found on buildings in the U.S.
Exterior Walls with Siding
| Exterior Walls with Siding Concrete block (8") | R-Value |
| Concrete block (8") | 2 |
| with foam insulated cores | 20 |
| with 4" on unisulated stud wall | 4.3 |
| with 4" insulated stud wall | 14 |
| Brick (4") | R-Value |
| with 4" uninsulated stud wall | 4 |
| with 4" insulated stud wall | 14 |
| Wooden Frame | R-Value |
| Uninsulated with 2" x 4" construction | 4.6 |
| with 1 1/2" fiberglass | 9 |
| with 3 1/2" fiberglass; studs 16" o.c. | 12 |
| with 3 1/2" fiberglass and 1" foam | 20 |
| StrongGreen™ Structural Panel | R-Value |
| 3 1/2" thick polyurethane panel X 24" Wide | 27 |
| 6" thick polyurethane panel | 45 |
| 3 1/2" thick polyurethane panel w/ceramic coating | 47 |
| 6" thick polyurethane panel W/ceramic coating | 65 |
Floor
| Floor Over unheated basement or crawl space vented to outside | R-Value |
| Uninsulated floor | 4.3 |
| 6" fiberglass floor insulation | 25 |
| Over sealed, unheated, completely underground basement | R-Value |
| Uninsulated floor | 8 |
| with 1" foam on basement walls | 19 |
| with 3 1/2 fiberglass on basement walls | 20 |
| Insulated floor, 6" fiberglass | 43 |
| Concrete Slab | R-Value |
| No insulation | 11 |
| 1" foam perimeter insulation | 46 |
| 2" foam perimeter insulation | 65 |
| StrongGreen™ Structural Panel | R-Value |
| 3 1/2" thick polyurethane panel X 24" Wide | 27 |
| 6" thick polyurethane panel | 45 |
| 3 1/2" thick polyurethane panel w/ceramic coating | 47 |
| 6" thick polyurethane panel W/ceramic coating | 65 |
Exterior Doors
(Excluding sliding glass doors)
Calculate glass area of door as window
(Excluding sliding glass doors)
Calculate glass area of door as window
| Wood Door | R-Value |
| 1 1/2" no storm door | 2.7 |
| 1 1/2" with 1" storm door | 4.3 |
| 1 2/3" solid core door | 3.1 |
| Steel with Foam Core Door | R-Value |
| 1 3/4" Pella | 13 |
| 3/4" Therma-Tru | 16 |
Roof / Ceiling
| Material | R-Value |
| No Insulation | 3.3 |
| 3 1/2" fiberglass | 13 |
| 6" fiberglass | 20 |
| 6" cellulose | 23 |
| 3 1/2" thick polyurethane panel X 24" Wide | 27 |
| 12" fiberglass | 43 |
| 6" thick polyurethane panel X 24" Wide | 45 |
| 12" cellulose | 46 |
| 3 1/2" thick polyurethane panel w/ceramic coating | 47 |
| 14" cellulose | 54 |
| 6" thick polyurethane panel W/ceramic coating | 65 |
| Glass | R-Value | Low Emissivity | Drapes | Quilts |
| Single pane | 0.9 | 1.1 | 1.4 | 3.2 |
| Single w/storm window | 2 | 2.5 | 4.2 | |
| Double pane, 1/4" air space | 1.7 | 2.2 | 4 | |
| 1/2" air space | 2 | 2.99 | 2.5 | 4.3 |
| Triple pane, 1/4" air space | 2.6 | 3 | 4.8 |
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