What is the R-value of blown-in attic insulation?

2.2 to 2.7 per inch
Blown-in fiberglass has an R-value of 2.2 to 2.7 per inch. Batts. Fiberglass batts and rolls are ideal for placement between framing during construction in floors, walls, attics, and ceilings.

What is the R-value of rolled insulation?

Like batts, standard fiberglass rolls have R-values ranging from R-2.9 to R-3.8 for every inch of thickness. High-density insulation rolls can have R-values as high as R-4.3 per inch.

Does blown-in insulation lose R-value over time?

Over time, the aeration in cellulose insulation will decrease. This settling will cause cellulose insulation to lose up to 20 percent of its R-value. By blowing in about 20 percent more insulation, you can account for settling.

How many inches of blown insulation should be in my 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.

How thick does blown insulation need to be?

When blown into attics and wall spaces, loose-fill fiberglass offers an average R-2.5 thermal value per inch (the higher the number, the greater the insulating effect). You’d need a thickness of about 7.5 inches of insulation to match the insulating value of a batt of R-19 insulation (R-19 is a common batt value).

Is adding insulation to attic worth it?

According to the Department of Energy, properly insulating the attic can save 10 to 50 percent on a typical heating bill. For many homeowners, insulating the attic is the most effective method to save on energy costs.

How many inches of insulation should be in my attic?

How long does insulation take to settle?

Most of the settling will occur in the first couple of months, but the cellulose will continue to settle for up to two years.

What is the R-Value of 10 inches of blown insulation?

R-value of Materials and Depths
Material R-value/in 10″
Mineral Wool blown (wall) 3.1 – 4.0 31.0 – 40.0
Cellulose blown (attic) 3.2 – 3.7 32.0 – 37.0
Cellulose blown (wall) 3.8 – 3.9 38.0 – 39.0

How do you calculate blown in insulation?

The standard calculation given by manufacturers for blown insulation is the number of bags per 1,000 square feet required to achieve a desired R-value. Depending on the manufacturer, this number ranges from around 12 to 15 bags per 1,000 square feet for an R-value of 26.

What is the best your value in insulation?

The insulation with the highest R value is, perhaps ironically, nothing at all. That is to say, a vacuum provides the most ideal insulation. Vacuum insulated panels have an R value of as high as 50, compared to approximately three for conventional fiberglass insulation.

How to calculate existing R-value in an attic?

How to Calculate Existing R-Value in an Attic 1. Wear a dust mask, gloves and a long-sleeved shirt when working with insulation. Fiberglass and other insulation… 2. Access the attic through the pull-down ladder already installed in your home, or with a stepladder placed so you can… 3. Extend a

What is the recommended your value for an attic?

Currently, the recommended R value for attic insulation is between 6.1 and 7, a combination of thickness and conductivity. Knowing where you stand with the recommended R value for attic insulation will ensure that you receive the right insulation for your home.