How to Install Insulation in Roof Rafters

Take one end of your rafter baffle and extend it approximately 4 inches into your attic’s eave. Position the baffle so that it is centered between the rafters. Use a staple gun and insulation staples, spaced approximately 12 inches apart, to attach the lips of the baffle to your roof deck. Repeat this technique on each pair of attic rafters.

Stretch the rafter baffles so that they extend from the eaves to the peak of your roof. Staple the baffles to the roof deck. Space your insulation staples approximately 12 inches apart. Use a utility knife to trim any excess baffle material.

Use a tape measure to measure the distance from the eave of your roof to its peak. Unfurl a roll of batt insulation. Check with your local building codes to determine the proper R-rating of installation for your geographic area.

Copy the measurements of your rafter’s length onto the batt insulation. Press down on the insulation with one hand, and use a utility knife to cut the insulation along those measurements.

Position one length of insulation, with the paper backing face down and the fiberglass side facing the rafter baffle, against the rafter’s peak. Use insulation staples to secure the flaps, located on either side of the batt insulation, to the bottom of the rafters. Space the staples 3 feet apart. Repeat this step with every set of rafters.

Staple insulation staples from the eave to the peak of the roof along each rafter. Space the staples approximately 12 inches apart. The staples will secure the insulation flaps to each side of the rafters.