FAQs
On this chart, each part of the country is divided into different zones and each zone has a recommended R-value. We can see that Sacramento and most of California are in Zone 3, which requires attic insulation with an R-value between 30 and 60.
What R-value do I need in Kansas? ›
According to the Energy Star recommended guidelines from the U.S Government; Kansas City homes, which are in Zone 4, should have at least 18″ inches of R49 insulation on the floor of the attic. These guidelines are for existing wood-framed homes.
What is the desired R-value for an attic? ›
R-Value is a measure of insulation's ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
What is the best R-value for exterior walls? ›
According to the U.S. Department of Energy, R-values for exterior walls in colder climates should be at least R-13 to R-23. In milder climates, a lower R-value may be sufficient. For example, in a moderate climate, an R-value of R-13 to R-15 is typically recommended.
Can you over insulate a house? ›
It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.
What is a good R-value for winter? ›
For winter camping, you generally want an R-value of at least 5, while three-season campers only need an R-value of 2 or more for most conditions. R-values are additive, so stacking two pads on top of each other provides an R-value that is more or less the sum of their individual R-values.
Can you over insulate an attic? ›
Excess insulation in the attic can make a house too tightly sealed and block vents. If airflow is blocked, moisture can't escape. If moisture accumulates in the attic and comes into contact with warm air, that can allow mold to grow, which can result in serious respiratory problems in people.
Is R6 insulation worth it? ›
As our highest rated option, Earthwool® R-6.0 Ceiling insulation offers superior performance, with the ultimate in energy saving properties, enabling you to keep your home cool in summer and warm in winter.
What is the highest R-value for a 2x4 wall? ›
Fiberglass and rock wool batts—2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products. Generally, batt insulation is the least expensive wall insulation material but requires careful installation for effective performance (see page 4).
Does doubling up insulation double the R-value? ›
Doubling the amount of insulation will double the R-Value, but so what? Doubling the insulation from R-19 to R-38 does NOT cut the heat loss in half (50%) it cuts it by around 3%!
Faced insulation is best for locations prone to moisture, while unfaced insulation is best for dry, interior locations. Unfaced insulation is more sound-proof and cost-friendly. Faced insulation is more fire-resistant and costly. Inspect your insulation annually to make sure it hasn't fallen.
Is R19 or R30 better for attic? ›
If your attic has 2-3″ of existing insulation, you'll want to install an R-30 to achieve a total of R-38. If your attic has 5-6″ of existing insulation, you'll want to install an R-19 to achieve a total of R-38.
Does drywall have any R-value? ›
The higher the R-value, the more effective a material is at preventing heat transfer. Drywall has a low R-value of 0.5. While it is slightly effective at preventing heat transfer, it is not considered an efficient insulator. This is probably due in part to the porous nature of drywall.
What is the strongest R-value insulation? ›
Rigid foam is the clear winner if you're looking for the highest R-value home insulation you can get. With an R-value of R-4 to R-6.5 per inch of thickness, it's ideal for insulating exterior walls, including basem*nt walls.
Is there a big difference between R13 and R15? ›
R-value is a metric that tells us how well insulation performs at reducing heat loss. When comparing R13 to R15, insulation designated as R15 performs better at reducing heat loss than R13. R-values are generally cumulative, meaning that you can stack two layers of R6 insulation boards to achieve R12.
Is an R-value of 4.5 good? ›
The higher the R value, the more your mat resists heat loss and the better it insulates you from the cold ground. As a rule of thumb, an R value of 1.0 to 2.0 is fine for summer use but you'd need a rating of 4.0 to 5.0+ for winter camping.
Does higher R-value mean better insulation? ›
R-Value is a measure of insulation's ability to resist heat traveling through it. The higher the R-Value the better the thermal performance of the insulation.
Is an R-value of 15 good? ›
Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces. Use the JM insulation calculator to determine the recommended R-value for your project, as well as how much insulation you'll need.
What is considered a bad R-value? ›
- if R-squared value 0.3 < r < 0.5 this value is generally considered a weak or low effect size, - if R-squared value 0.5 < r < 0.7 this value is generally considered a Moderate effect size, - if R-squared value r > 0.7 this value is generally considered strong effect size, Ref: Source: Moore, D. S., Notz, W.