Table of Contents
First, you will need to Measure Your Roof. See the example at the bottom of the page.
Radiant Barrier on top of the Insulation
Going up the Trusses
Why do you need Radiant Barrier?
The attic insulation will heat up because of radiant heat from the sun, making the attic and interior of your home hot. A radiant barrier reflexed the heat back to the roof, which helps prevent the attic insulation from heating up. Excellent attic insulation means a more comfortable home.






Measure Your Roof, Estimate
First, measure the outside length and width or what is known as the footprint of your home. Multiply that by the roof slope factor.
Example
For example: If the foundation measured 50′ x 30′, the foundation and footprint of the attic would be 50 x 30 =1500 sq ft.
Now that you have the footprint or square footage of the attic space. Multiply the total roof square footage by the relevant pitch factor to complete your estimate for the amount of foil you will need to cover the roof slopes.
50 x 30 =1500 sqft footprint
X 1.3 pitch is 6/12
= 1950 sqft of Radiant Barrier Plus to cover your attic floor and roof rafters.
Multiply it by 1.2 to 1.3, If your roof is under a 5/12. The rooftop is easy to walk on and probably under 8′ at the highest point like most homes.
Multiply by 1.3 to 1.4: If your roof is a 6/12 thru 8/12 pitch ( slightly difficult to walk up with a ridge usually over 8′ high).
Multiply by 1.4 to 1.5: If your roof is a 10/12 pitch or higher ( very difficult or impossible to walk up, this is often considered a very steep or church-style roof)












Do’s and Don’ts:
Don’t – It is a DIY simple Product, do not overthink it.
Don’t – worry about hard-to-reach areas; Radiant Barrier is like shade. It has a cumulative effect. The more, the better.
Do – Work on open areas first, then worry about the other sites.
Do – Having a friend to help it will make it easier.
Don’t – cover holes in the bottom and holes in the top of the attic. Is there a path for air to flow from the bottom holes to the top spots? If yes, then you are good. If not, create a pathway.
Don’t – worry about the look of the Radiant Barrier Remember, it is your attic, not your living space.
Don’t – tape the seams; it is optional.
Don’t – worry; it is simple.
Do – safety first! A wood plank across the ceiling joist will help you around. Watch out for nails coming through the roof deck.