How to Insulate a Garage

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Things You'll Need

  • Fiberglass insulation batting

  • Staple gun

  • Utility knife

  • Straightedge

  • Plastic sheeting

  • Power drill

  • Insulation blower

  • Blown insulation

  • Tube of window caulk

  • Caulk gun

How to Insulate a Garage. Many people want to convert their garages into workshops or an extra living space. However, unlike houses, garages are rarely insulated. Follow these steps to prepare your garage for year-round use in any climate.

Insulate Exposed Walls

Step 1

Place insulation in between 2" x 4" wall studs. The insulation should be attached to the 2" x 4" studs with the insulation facing away and the paper side visible.


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Step 2

Staple paper edges to the 2" x 4" studs every 12 inches.

Step 3

Cut insulation to fit, using a sharp utility knife and a straightedge. Make sure there are no gaps in the insulation.


Step 4

Repeat for each gap.

Step 5

Pull vapor seal plastic film tight and staple at least every 12 inches. Start at the top of one corner of the garage.

Step 6

Overlap the sheets by one complete cavity, working around the entire room.


Step 7

Trim out the plastic from over windows, doors and electrical boxes using utility knife.

Step 8

Staple around the windows, doors and electrical boxes to ensure a tight vapor seal.

Insulate Walls That Have Been Drywalled

Step 1

Drill a small hole in the drywall between the studs at the top of the wall.


Step 2

Blow insulation into gap, using slow-curing foam or fiberglass insulation. There are many makes and models of insulation blowers. Follow the manufacturer's directions at all times.

Step 3

Repeat for each gap, moving around the room.


Seal Windows and Doors

Step 1

Insert caulk tube into caulk gun.

Step 2

Snip off tip of caulk tube with a utility knife.

Step 3

Gently squeeze caulk gun handle as you move along the seam of each area. Apply caulk around all window and door frames.