How to Insulate a Basement Walls with Fiberglass Insulation

Is your basement cold? Do you notice that the main floors of your house are cold in the winter months? If so, these are good indications the problem lies in the fact you need to insulate your basement to keep the cold air out. Whether your basement is made of brick, concrete blocks, or sandstone blocks, if it’s not protected from the cold outside temperatures, then your heating dollars are going right out through the walls. Therefore, you need to know basically how to insulate your basement.

You can insulate your basement walls even if you’re not a skilled carpenter or handyman around the house. You don’t need a lot of special tools or equipment.

Did You Know? According to the United States Department of Energy, a basement that’s not insulated can allow as much as 30% of a home’s heat escape through the walls.

The first step in this project, before you do anything else, is to inspect your basement.

Check the walls for cracks and holes that can allow cold to leak in. (These can also allow water to leak in too!) Most holes and cracks can be plugged shut by using premixed cement or another kind of product. You can find the right product, along with a trowel, to do the job with by visiting your local home supply store. Be sure that you read and follow the manufacturer’s directions on the container in order to achieve the best results.

Once any holes are cracked are plugged shut, you’re ready to insulate your basement and make it, as well as the rest of your house, warmer and more comfortable. Not only that, but it will also help lower your cooling bills in the hot summer months.

The most common way to insulate your basement walls, no matter what they are made of, is to use fiberglass roll insulation.

fiberglass insulation in a walls
fiberglass insulation in a walls

Fiberglass roll insulation comes in a variety of “R-values.” The R-value of insulation refers to its ability to resist heat transfer. Or, simply put, the higher the R-value is when it refers to insulation, the more effective it is in blocking out cold or hot air. When you visit your local home supply store, a sales associate can help you determine what type of fiberglass roll insulation you need.

Rolls of insulation are available in either fifteen or twenty-three-inch wide rolls. The rolls normally measure up to twenty-five feet long for quicker installation.

Before you hang the rolls of insulation, you’ll need to install wood studs either fourteen or twenty-two inches apart, depending on the width of the fiberglass roll insulation you choose, on your basement walls. Two by fours work well for this application. The two-by-fours are nailed to the walls of your basement by using hardened concrete nails.

Once you have the studs installed, you’ll need to put on a dust mask and a pair of gloves to protect your respiratory system and your hands from the fiberglass particles. Then, measure the length of one wall, unroll the insulation, and cut off a strip that will fit. You can use an old air of sharp scissors for this step.

Take the strip of the fiberglass roll insulation and start pressing it snugly into place between the wall studs on your basement walls. Then, staple the insulation securely to the wood.

Repeat this process all the way around the entire basement. However, for safety’s sake, keep the insulation three inches away from any chimneys, flues, and other heat sources.

Once you’re finished installing the fiberglass roll insulation, you should cover any seams and tears with pieces of duct tape.

And finally, you shouldn’t leave fiberglass roll insulation uncovered. You can cover it up with sheets of Gypsum drywall or with wood paneling.

Instead of using fiberglass roll insulation, you may choose to use sheets of inflexible insulation. These sheets are secured to the studs using an adhesive. The sheets of insulation and the adhesive are available at your local home supply store too.

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About the author
Ben White has written thousands of articles on everything home improvement. He has had the privilege of writing for such websites as the Huffington Post, DeWalt,, HGTV, and many others.

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