The Right Way to Insulate Your Basement

The Do’s and Don’ts of Basement Insulation

The basement is one of the most important areas of your home to insulate properly. It’s often the most musty smelling, draftiest room in the house. But it doesn’t have to be. The goal of basement insulation is to control the temperature and keep mold and mildew out. Here are some guidelines for achieving these goals:

Get rid of that musty smell

Many basements smell bad. It’s such a common problem, but it doesn’t have to be that way. The reason for this is that most basements have concrete walls, and concrete is notorious for absorbing moisture. This creates that musty odor that many of us know all too well.

Before you install insulation, first check that you don’t have a more serious moisture infiltration problem. If you see any water on the foundation on a normal day, you may need to put in a drainage system first.

Understand your basement insulation options. Sometimes the most popular basement insulation products aren’t always the best. For example, fiberglass batts cost less than other types of insulation, but aren’t the best choice for insulating a basement (see below). A batt is basically a roll or blanket that’s made of fibers like wool or fiberglass. There is also rigid foam insulation, which is more expensive, but more effective, than fiberglass. They come in sheets or panels of extruded polystyrene or XPS. One to two inches of rigid foam will be a solid moisture deterrent. Keep in mind that XPS is a flammable material, so you’ll need to install a thermal barrier—a half-inch of gypsum board should do the trick.

Be cautious about using fiberglass insulation. It’s not recommended that you apply fiberglass insulation directly to a concrete wall. If you must use fiberglass, there needs to be a space between the insulation and the wall. If not, the place where the insulation touches the concrete will be overtaken by mold and mildew. Remember, fiberglass does NOT resist moisture, so it’s generally a no-no when insulating basements. You can reduce the risk of moisture issues if you first cover the concrete with a continuous layer of rigid foam or closed-cell spray foam. Then contractors may install a wall on the interior side of the foam insulation and put fiberglass batts inside the stud bays. While this is better than applying fiberglass directly to concrete, it’s even better to use closed-cell spray foam to insulate your basement.

Consider the benefits of spray foam in your basement. Closed-cell spray foam is the best way to insulate concrete basement walls. This is because it can achieve a higher R-value, along with excellent moisture resistance, with less thickness required. It can fill in all the gaps and spaces thoroughly, giving you the best protection against moisture and air infiltration. It’s a more expensive option, but you’ll save money in energy bills, not to mention the cost of doing damage control after mold and mildew are already serious problems.

Choose whether to insulate the interior or exterior walls. Do you want to insulate your basement walls from the inside or the outside? Usually, insulating the outside occurs when a house is first being constructed. Exterior wall insulation is considered the best choice for optimum energy efficiency, too. However, interior insulation is easier and more cost-effective for many homeowners. If your basement has already been constructed but is still unfinished, it’s a more practical choice to insulate the interior.

Keep in mind, both approaches work well and depend on what’s most important to you. For example, if you insulate the exterior walls, you’ll have more space inside the basement. When you insulate the interior walls, you’ll be able to have an uninterrupted connection between the below-slab insulation and the wall insulation. If you’re building a new home, interior wall insulation also works better with the construction schedule. All of these factors are important to consider when planning your basement insulation.

We recommend that you don’t undertake a project such as insulating areas of your home without consulting with professional contractors. There are many potential pitfalls to doing it yourself. When you call on experts, you can avoid unnecessary expenses from trying to fix mistakes, and you can feel secure that you’ll have it done right the first time.

At Superior Insulation Company, we’ll be happy to talk with you about all of your insulation needs. We are your partner in smart residential, commercial or industrial insulation. Contact us today to get started.