How to Insulate an Attached Unheated Garage

Unfinished Ceilings

• 1

  Unroll the insulation. Measure and cut it into sections no longer than 12 feet to make it easier to handle.

• 2

  Attach 2-foot long bar clamps to the ceiling joists where the insulation is being installed.

• 3

  Thread the insulation through the clamps. Start in the middle of the ceiling and work towards one side, and install the insulation so the exposed fiberglass is facing the roof.

• 4

  Pull the edges of the paper towards the sides of the ceiling joists and staple the paper to the joist every 6 inches. Finish installing the insulation in that row of the ceiling. If there are any spots where the insulation is above the walls, gently tap it down with a 2-by-4 to fill the gap.

• 5

  Finish installing the insulation in the rest of the ceiling. If there are any fixtures such as lights or electrical outlets, install the insulation above them. Cut a hole in the insulation around the fixture, then tamp the insulation in place.

Walls

• 6

  Measure the space from the ceiling to the floor.

• 7

  Unroll the insulation and cut it to fit the wall.

• 8

  Gently fit the insulation into the gap between the wall studs with the exposed fiberglass facing away from you. Allow it to fully expand. Place the insulation over any fixtures such as outlets and light switches, then cut a hole to accommodate the fixture and press the insulation against the wall.

• 9

  Staple the paper to the inside of the studs every 6 inches.