How to Install Ceiling Insulation

A home or garage has many places that may require insulation and include the ceiling. Access an attic or crawlspace to reach the ceiling in your house or garage. A typical ceiling has rafters that span the width of the house that are usually covered on the bottom side with drywall. Installing insulation should be done shortly after a new ceiling has been installed.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Utility knife

1. Determine what type of insulation to use. A ceiling with rafters can be insulated using fiberglass batts that are bundled rolls 6 inches to 8 inches thick.

2. Determine the appropriate R-value that will suit your needs. Use the form on the Department of Energy's website (see Resources) to find the R-value that is recommended.

3. Measure the spacing between the rafters in the ceiling. The standard width between rafters is typically 16 inches. Anything less will require cutting the insulation to make it fit properly.

4. Measure the length of the rafter to determine how long a piece of insulation will be needed. Use a utility knife to cut the required length of insulation.

5. Place the insulation between the studs in the rafter. Use a utility knife to cut the insulation to fit around air ducts and pipes.

6. Repeat Steps 4 and 5 until the ceiling has been completely insulated.

Tips & Warnings

• Use blown insulation as an alternative to fiberglass. Blown insulation may require renting a compressor from a home improvement store.
• Wear proper protection, which includes a long shirt, pants, gloves, a mask and eye protection. Do not step directly on the drywall or you will put a hole in the ceiling. Blown insulation has a tendency to settle over time, which reduces the R-value. Building codes may forbid using blown insulation in older homes.

Resources

• R-value calculator