What is a good R-value for attic insulation?
What is a good R-value for attic insulation?
Recommended insulation levels for retrofitting existing wood-framed buildings
| Zone | Add Insulation to Attic | |
|---|---|---|
| Uninsulated Attic | Existing 3–4 Inches of Insulation | |
| 1 | R30 to R49 | R25 to R30 |
| 2 | R30 to R60 | R25 to R38 |
| 3 | R30 to R60 | R25 to R38 |
How many inches of blown in insulation is R38?
12.75”
Fiberglass Chart
| R-Value | Thickness | Bags / 1000 Sq Ft |
|---|---|---|
| R49 | 16.25” | 22.6 |
| R44 | 14.75” | 20.1 |
| R38 | 12.75” | 16.8 |
| R30 | 10.25” | 13.0 |
What is a good R-value per inch?
Comparative Insulation R-Values
| Insulation Type: | R-Value per Inch: |
|---|---|
| Fiberglass (loose) | 2.2 – 2.9 |
| Fiberglass (batts) | 2.9 – 3.8 |
| Cellulose (loose) | 3.1 – 3.8 |
| Stone Wool (loose) | 2.2 – 3.3 |
How many inches of attic insulation do I need for an R30?
9 inches
In Zone 1, the average minimum requirement for attic insulation is 9 inches of R30 fill. The average recommended level is 14 inches of R49. In Zone 2, the average minimum requirement for attic insulation is 9 inches of R30 fill. The average recommended level is 17 inches of R60.
Can you have too much insulation in your attic?
It’s possible to over-insulate an attic as too much will cause moisture buildup and eventually result in mold. Eventually, adding more insulation leads to diminishing returns in trapping heat as well.
How thick is r38 insulation?
The R-38 high-performance batts are 10˝ to 10-1/4˝ thick as opposed to stan- dard R-38 fiber glass insulation batts of 12˝.
How many inches of blown insulation is r60?
If you have approximately 6″ of existing insulation, you’ll need to add an additional 17″ to reach R-60. If you have approximately 10″ of existing insulation, you’ll need to add an additional 13″ to reach R-60. If you have no insulation, you’ll need 23″ to reach R-60.
How thick is r30 insulation?
8¼ ” thick
8¼ ” thick, R-30C EcoTouch® Thermal Batt insulation prevents moisture damage and helps assure long roof life by providing 1″ of ventilation air space between the insulation and roof deck. Easy Installation R-30C EcoTouch® Thermal Batt insulation is easy to handle and install.
Which insulation has the highest R-value per inch?
rigid foam panels
Among insulation types, rigid foam panels have the highest R-value per inch.
Can I have too much insulation in my attic?
What is the R-value of 2 inches of closed cell foam?
This microscopic difference in the two products creates a dramatic difference in performance. Closed cell spray foam has an R-value of R-7 per inch. In comparison, open cell spray foam has an R-value of R-3.8 per inch. Additionally, the materials have decidedly different densities.
