Instructions for Insulating Pipes in the Attic

A wrench and some pipes laying on top of blueprints.
  • 1 hours
  • Beginner
  • 30-60
What You'll Need
Utility knife
Duct tape
Plastic foam

When insulating pipes in the attic, there are some steps you need to follow. Insulating your pipes reduces heat loss and keeps cold pipes from sweating in warm weather. The process for insulating attic pipes is no different than insulating other pipes in your home. This how-to article will provide the steps for insulating your pipes.

For starters, a little tip: don't use a spray material that contains a cork as an insulator for your pipes. This material requires several applications with either a sprayer or paint brush and can become messy. It also does not give you an appealing look, and if not properly installed, may not completely insulate your pipes. If you do want to completely insulate them, here's what you do.

Step 1—Choose an Insulation

The first step in the process is to choose insulation for the pipes. Choose a plastic foam, wood felt, or fiberglass material. The insulation will have a slit at the top to allow it to cover the pipe easily. You should also choose an insulation material with a high R-value. The R-value measures the efficiency of an insulator. For cold climates, a higher R-value is needed, but, for warm climates, you do not need insulation with such a high R-value.

Be sure to purchase enough insulation to cover all of the pipes in your attic. Measure the length of the pipes being covered in order to determine how much is needed for the installation.

Step 2—Locate Pipes

You will need to locate the pipes in your attic, obviously, to measure them and know what level of difficulty you will have in covering them. For some homes the pipes will run underneath a subfloor or at the bottom of the attic; for other homes the pipes might be located in the walls or the roof rafters. Find out where the pipes are located to see if a ladder is needed to reach them or if you will have to work on your knees installing the insulation.

Step 3—Place Insulation on Pipes

Once you locate the pipes, take the insulation and cut it into sections using the utility knife in order to easily slip it over the pipe. Open the insulation piece at the slit and slide it over the pipe. Continue this process over the entire length of piping in your attic.

For corner joints that need to be insulated, cut a simulated miter joint by cutting the insulation at a 45 degree angle. This will allow you to slip the insulation over the pipe corner easily.

Step 4—Secure Insulation

With the insulation in place, use duct tape to join any seams and secure it to the pipe.