Home Improvement

What is the R value of 12 inches of insulation?

Blown fiberglass installed in the attic has an R-value of 2.2 per inch, so 12 inches of it would give you an R-value of 26.4 in your attic installation project.

What R-value is 10 inches?


That means that 10 inches of mineral wool will have an R-value of R-37. Here are some estimates to illustrate how important good insulation (high R-value materials) really is: Poorly insulated buildings will experience heat loss (winter) and heat gain (summer) as high as 50%.

What is the R-value of 12 inches of loose fill fiberglass insulation?

R-2.5 per inch

Loose-fill fiberglass: R-2.5 per inch (12-20 inches thick for an attic) Cellulose: R-3.7 per inch (9-14 inches thick for an attic)

How many inches is R30 insulation?

Typical R-30 fiberglass insulation is 10-inches-thick. Prior to buying fiberglass insulation, it is important to measure the joint spacing you are working with.

What is the R-value of 14 inches of blown insulation?

Cold Climates (R-49 to R-60):

Fiberglass (batts): 14” – 19” Cellulose (blown): 14” – 18” Rock Wool (loose): 17” – 25”

How many inches of insulation is R38?

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 the best R-value for 2×4 walls?

Insulation for 2×4 Walls

In most wall applications, you will use R-13 or R-15 kraft-faced fiberglass insulation rolls for these two-by-four stud walls. While rated differently, these two types of insulation are close enough in thickness that they can both fit into modern two-by-four wall systems.

Can you put too much blown insulation in your attic?

Can you over insulate your attic? The answer is yes! Past a certain point, insulation in a vented attic will do more harm than good. In most of the United States, achieving an R-Value of 38 is more than sufficient.

How thick is r38 insulation batts?

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˝.

What is the R-value of 6 inches of spray foam?

Spray Foam Insulation R-Value

Open cell spray foam insulation is R-3.6 to R-3.9 per inch. This R-Value is normal for open cell spray foam. Closed cell spray foam insulation is R-6 to R-7 per inch.

What is the R-value of 5 1/2 inch fiberglass insulation?

Even in a 5 1/2-inch wall, the R-19 (which is rated at 6 inches of thickness) gives you only R-18. For the best performance, any batt should be installed carefully, to fill the entire space without compressing around wires, pipes, bridging, or other obstructions.

What R-value is 6 inches of insulation?

Fiberglass blankets or rolls provide an R-value of up to 3.2 per inch, so a 6-inch fiberglass batt may achieve an R-value of 19.2, and some high-performance products are rated at R-21.

Does doubling insulation Double R-value?

Doubling the thickness of insulation will double the insulation’s R-value, cutting heat loss in half. Each time the insulation layer is doubled in thickness, this rule applies.

What is the highest R-value for a 2×6 wall?

Thermal Control

The installed insulation R-value for 2×6 fiberglass batt ranges between R-19 and R-21. When blown or sprayed cellulose insulation is used, the R-value is typically R-20 for 2×6 walls.

What is the R-value of spray foam in a 2×4 wall?

Open-cell spray foam absorbs and holds water. It has a lower R-value per inch than closed-cell foam and is vapor-permeable. The R-value is R-3.5 to R-3.6 per inch, so filling a 2×4 cavity yields about an R-13.

Can I put r19 in a 2×4 wall?

While you can stuff r19 insulation into a 2×4 wall, it is typically not the best way to go about boosting your home’s insulation rating. R19 insulation is meant to fit 2×6 walls. Cramming the insulation into a smaller area might seem like a good idea, but it ultimately won’t result in the r19 rating you would expect.

Which is better spray foam or fiberglass insulation?

Spray foam insulation has a higher R-value than fiberglass, making it a better insulator. Another difference between them is that spray foam is watertight while fiberglass cracks under moisture. However, installing spray foam requires a professional while fiberglass is easy to install yourself.

What is the thinnest insulation with highest R-value?

Aerogel insulation

Aerogel insulation offers the highest R-value of any insulating material at less weight and thickness—ideal for construction, refineries, pipelines, and thin-gap thermal barriers.

What material has the highest R-value per inch?

rigid foam panels

Among insulation types, rigid foam panels have the highest R-value per inch.

What is a good R-value for exterior walls?

R-13 to R-23

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. See the Department of Energy’s (DOE) ranges for recommended levels of insulation below.