How Much RadiantGUARD® Do You Need For An Attic

In order to purchase the right amount of RadiantGUARD® radiant barrier products, you need to know the method of installation you intend to follow as well as the square footage of the area you intend to protect from the radiant heat.

Laying Over Attic Floor

If you intend to lay the radiant barrier over the attic floor, you need to know the square footage of the area of your attic. 

  • If your attic covers your entire home and your home is one story, then the square footage area of your attic should be the same as the noted square footage of your home based on your last appraisal.

  • If your home is a two stories, you will need to know the "footprint" square footage of the second story which the attic covers.

Stapling to Underside of Rafters

If you intend to staple the insulation to the underside of the roof rafters, you need to know the roof area square footage calculated as follows:

  1. Multiply the length and width of the roof  to find the footprint square footage.

  2. Based on the ***slope/pitch*** of your roof, multiply the footprint square footage by the appropriate factor listed to the right.

The resulting number is the roof area square footage.  You should purchase enough material to cover this square footage amount keeping in mind that each radiant barrier piece is to be overlapped by 1-2 inches.

Note:  If you have a gable or hip roof, you will need to measure each section separately using this technique and the add the amounts to get the total roof area square footage.  If you intend to cover the gable ends as well, don't forgot to include those in your calculations.

Pitch Factor
1:12 1.01
2:12 1.02
3:12 1.03
4:12 1.05
5:12 1.08
6:12 1.12
7:12 1.16
8:12 1.20
9:12 1.25
10:12 1.30
11:12 1.36
12:12 1.41

**** "Slope/pitch" = the number of inches a roof rises ("rise") for every foot of horizontal travel ("run".)   Communicated as inches of rise:12 inches of run