How to Install Crawl Space Insulation

What You'll Need
Rolled insulation
Heavy duty stapler
1/2-inch staples
Wire hangers
Tape measure
Utility knife
Safety glasses
Face mask
Plastic sheating

For many homes with a crawl space there will come the time when you need to install, or even replace, the insulation. Whether it is due to the insulation falling because of moisture, or because of rodents, installing crawl space insulation is not a difficult job to do in terms of skill needed. However, it can be rather daunting for those who do not like tight spaces.

Step 1- Measure Crawl Space

Start at one edge of the crawl space and measure the distance between from each side. Then measure the length of the crawl space. Multiply those two numbers together for the square footage. When you are at the home center, look on each roll of insulation for the amount of square feet a roll will cover. This number will be different depending on the thickness of the insulation.

Step 2- Remove Old Insulation

Put on your protective gear and begin removing the old insulation. Start in one corner and begin removing the insulation in long strips. Resist the temptation to just rip it down into tiny pieces. By removing long strips you will be able to roll it back up and dispose of more easily. Roll it up and put it into bags before taking to the landfill.

Step 3- Install Insulation

Take the first roll of insulation and roll it out to its full length. It is better to keep the insulation in one piece if you can. If the roll is too long, measure how long the first strip will be. Transfer this measurement to the insulation and cut off the piece with a utility knife. Stick the edge in between the joists at the farthest edge of your crawl space. Tack in place with the stapler by pulling the paper tabs out and stapling them to the joists.

Step 4- Install Wire Hangers

Once you have the first part of the insulation up, continue down the joist until you reach the end. Since the insulation will have the force of gravity pulling on it, you will need to also install wire hangers to help keep the insulation in place. These wire hangers span between the joists and can be tacked in with the staples. Install a wire hanger every two feet as you work your way through the crawl space.

Step 5- Install Plastic Sheating

One of the reasons that insulation begins to deteriorate after a few years is because there is no moisture barrier between it and the ground. Start at the same place you started installing the insulation and begin to roll out plastic sheeting. Keep the plastic doubled up and cut to size with the utility knife. Staple it to the joists going across them instead of in the same direction as they run. Overlap each new row by at least 6 inches. Let the plastic come down the side of the walls at least 10 inches.