Blown In Insulation R Value Per Inch

Atticat expanding blown in pink fiberglas insulation nominal bag weight 28 5 lbs.

Blown in insulation r value per inch.

Your home s age if your home is more than 10 year old you likely need more insulation. How is insulation r value calculated. Values are reported to the nearest fi ve 5 rating. There are many ways to retrofit a home with fiberglass and.

Therefore a three inch thick board has an r value of 3. However cellulose is inexpensive environmentally friendly and easy to install behind finished walls. R value bags per 1000 sq. Click the button to calculate the depth in inches and pounds of total insulation required for this job.

Input depth of existing blown in insulation in inches. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3. Click the button to calculate the approximate r value for this job.

You d need a thickness of. For example a wall with 3 fiberglass batting r value of 10 8 11 9 may have an overall r value of nearly 14 because of siding sheathing and drywall. Loose fill cellulose is rated between r 3 2 and r 3 9 per inch making it one of the least efficient insulation materials available. Let s start with an example.

Input length width and desired r value of the area to be insulated. Depending on where you live it s recommended that attics have a minimum r value of r 30 in warm climates to r 60 in cold climates. This calculator is to be used as an estimating tool only. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7.

Solid wood has an r value of 1. A particular end use. This calculator is to be used as an estimating tool only. Minimum thickness inches minimum settled thickness inches 13 5 9 168 5 0 169 4 75 4 75 19 9 1 109.

As a benchmark one inch of solid wood has an r value of 1. You only need four inches of r 3 5 cellulose in a wall cavity to exceed the recommended insulation level of r 13 for walls located in zone 4. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. 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.

An r value is also calculated per inch of width. As you can see there s some variation in r value depending on the particular type and brand of products used. Here are the most common insulation materials listed in order of lowest to highest r value. Maximum net coverage sq.