Insulating an Attic

Why install insulation in an attic?  A significant amount of heat is lost through the roof, which makes the attic an important area to insulate. Attic insulation works like a cap – it traps the heat inside, increasing comfort and efficiency and serving as the first line of defense when protecting against outdoor weather and temperatures.

Before beginning an attic installation job, it’s important to check your current insulation. When checking insulation in a previously insulated space, use a yardstick to check the depth. The average home needs up to 19 inches of fiberglass insulation in the attic for maximum energy efficiency.

If the space requires additional insulation, an easy fix is to place insulation batts or rolls in the attic’s floor joists, on top of any existing insulation. For specific instructions on how to install batts and rolls in the attic, check out this video.

If the attic is unfinished or doesn’t have existing insulation, installing blow-in insulation, like Attic Protector®, offers installation efficiencies in that it’s typically easier and less time-consuming than laying batts or rolls. Blow-in insulation can also be added on top of existing insulation to get the R-value you desire. Rent this equipment from a nearby retailer that that you buy your insulation from. 

Not ready to do it yourself? Find a contractor here.


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Attic Protector®

Attic Protector® blow-in fiberglass insulation fills those hard-to-reach cavities and corners in attics. With the help of a portable blowing machine – which can be rented from your local home improvement store – installation is easy and efficient.

Unfaced Batts & Rolls

JM Unfaced Formaldehyde-free™ fiberglass insulation offers R-values ranging from R-11 to R-38, as well as effective thermal and noise control.

Kraft-Faced Batts & Rolls

JM Kraft-faced Formaldehyde-free™ fiberglass insulation offers R-values ranging from R-11 to R-38, is ideal for moisture control in exterior walls and provides excellent temperature and noise control.


ComfortTherm® Formaldehyde-free™ fiberglass insulation is wrapped in plastic to reduce itch and dust during installation. It provides excellent temperature and noise control, and comes with a vapor-retarder or without a vapor-retarder for use in hot, humid climates.

Related How-To Guides

Install in an Attic

This video will show you how to insulate an attic, step by step, with precut batts and rolls.

Install Blow-In Insulation

This video will show you how to insulate your attic with JM blown-in attic insulation.