How to Insulate a Garage Roof

bare roof rafters
  • 8-10 hours
  • Intermediate
  • 200-600
What You'll Need
Utility knife and metal edges
Foil tape
Insulation rolls (preferably ones easy to cut into pieces)

One of the best methods you can use if you want to regulate the temperature of your garage is to insulate the garage roof. If your garage is attached to your house, you will notice a big difference in your home’s temperature as well. The regulating temperature has positive effects on your cooling and heating costs. The task of insulating a garage roof is not hard to complete if you follow a few tips and hints. Here is a guide on how you can insulate the garage roof in a few easy steps.

Step 1 – Choose the Type of Insulation

The first thing you need to do is choose the type of insulation you are going to use. There are two main types of insulation appropriate for use in garage roofs. Nonetheless, first, determine if you can buy a pre-composed insulation kit suitable for your garage. Purchasing a kit will save you both money and time. If you cannot find an insulation kit you need to choose which type of insulation to buy. The first main type of insulation is foam sheathing. This has a relatively high R-value, but can be somewhat inconvenient for the installer. Flexible and reflective insulation is another popular type of insulation. This type might have a lower R-value but is much easier to use and install since it comes in rolls. It doesn’t leave much waste either. Your choice of material depends on your budget and your overall confidence in working with the insulation. You can also choose the color of the insulation according to your door type and color.

Step 2 – Cutting the Insulation

After you have purchased the insulation, you need to cut pieces to fit in the roof and ceiling. Measure the ceiling to determine how large the insulation pieces will be. You should use a knife and a metal edge. If you have bought the flexible insulation you should consider cutting wider pieces since this type of insulation will bend into the cavities, creating a tight seal.

Step 3 – Install the Insulation

To install the insulation overhead, you need to staple the pieces to the roof trusses. Make sure that all of the pieces are the same size so that they fit into the trusses. You should use some foil tape to make sure that the insulation is stable on the roof edges. The tape will also make sure that there is an air pocket available in the insulation.

Extra Tip – Consult with a Professional

If you are indecisive about what type of insulation to use, consult an expert who is familiar with R values and insulation materials. You can also check the suggestions of the US Department of Energy. If you choose to install fiberglass insulation, remember to always wear protective glasses and a mask because fiberglass pieces can fall into your eye to cause injury or be inhaled and irritate your throat and lungs.