Standard Depth Of Blown In Fiberglass Insulation Attic

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Standard depth of blown in fiberglass insulation attic.

Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. To ensure an even distribution i cut a dozen dowel rods to match that depth and then spray painted their top halves a bright orange color. You d need a thickness of. Ten inches of blown insulation provides an insulating value of approximately r 30 1 inch of fiberglass provides about r 2 7 while 1 inch of cellulose is approximately r 3.

For instance if you have fiberglass insulation in your attic 12 inches deep the insulation has an r value of 30. A poorly insulated attic lets heat escape through the roof wasting energy used to warm. To arrive at r 38 you need at least 15 2 inches of blown in fiberglass insulation requiring you to add 3 2 more inches of insulation if you already have 12. Inspecting your attic insulation.

Click the button to calculate the approximate r value for this job. Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live. I wanted an r value between 49 and 60 in my attic so i settled upon a desired depth of twenty inches of insulation. This type of insulation comes in two types of densities medium and high which translates into an r 11 and r 15 for a standard 2x4 wall.

For loose fill cellulose this translates to a total depth ranging from 8 inches. Each bag of fiberglass insulation will cover approximately 65 square feet of attic space to a depth of 10 inches cellulose insulation covers half as much. Attic insulation is a key to saving energy during the heating season. This calculator is to be used as an estimating tool only.

First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. Fibreglass insulation material has no nutritional value for insects and less likely to get attacked by them. Input depth of existing blown in insulation in inches. 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.