How to Insulate Your Basement

Owning a home can be a major chore. You can’t merely dial up the landlord whenever problems arise. You as the homeowner are responsible for maintaining everything, including the basement.

In particular, you’ll want to insulate your basement, especially if you intend to use it as a gym, living area, or even a bedroom. The problem, however, is that every expert has his or her own list of the 10 best basement insulation methods. The truth is that there isn’t a single correct way. It all depends on your specific needs.

There are in fact hundreds of factors to consider, such as the type of basement, its size, your local building codes, and your budget. However, there are some basic basement insulation tips that you can follow.

The first step is to eliminate any chance of water migrating from the exterior basement walls into your finished basement rooms. One option is to rely on closed-cell, spray foam. It’ll provide a natural water barrier, while also covering wires and pipes, warding off cold temperatures, and adding a certain degree of additional structural integrity.

The only problem with this method is that it’s quite expensive. However, it is by far one of the most effective insulation methods.

Another option is to rely on foam boards. This is one of the more commonly used basement insulation methods, as well as one of the most inexpensive.

There are three types of foam boards you can choose from, including expanded polystrene, extruded polystyrene, and polyisocyanurate. Expanded polystrene is the most inefficient (rated 3.6-4.0 on the R-value scale), but it’s also the most affordable.

Extruded Polystyrene is middle-priced, lightweight, and fairly efficient (rated 4.5-5.0). Polyisocyanurate is the best, as it has a rating up toward 8.0. However, it’s extremely expensive.

Using fiberglass is also an option. It’s in fact one of the oldest basement insulation methods. In particular, fiberglass batting is cheap and supposedly green, though it’s not as effective as conventional foam insulation.

There is however also the option of using loose fill fiberglass, and having it literally blown onto stud cavities. This is more effective, but also approximately 30% to 50% more expensive according to the Corefront Website.

There is one last option. You can use both foam boards and fiberglass. It’s a hybrid methodology designed only for basements that have never been flooded or penetrated by any water.

The way it works is you first install foam boards, then seal them with tape or a spray foam. This is where it gets interesting. You must construct a frame out of either wood or steel, and place it in front of the foam boards. Now you merely apply fiberglass insulation to the stud cavities.

It’s an unusual method, but it’s been gaining popularity in the last few years.

Here are a couple more basement insulation tips to keep in mind. Don’t use plastic vapor barriers. Though they’re recommended for keeping moisture from penetrating standard home walls, this doesn’t necessarily apply to basement walls. Often times plastic vapor barriers will trap incoming moisture within the walls, thereby encouraging the growth of mildew and mold.

Weatherstrip your basement doors and windows. Either metal or vinyl will work well to keep your basement better sealed & insulated. In general, avoid relying on either felt or open-cell foam. Though they’re inexpensive, they’re not reliable when it comes to blocking drafts.

Don’t forget to insulate your floors. Carpet is okay, but it’s not going to provide much more than comfort and aesthetics. What you can do is place foam boards on the concrete floor. Then put a 1/2″ layer of plywood on top. Now secure it all with screws drilled into pre-made holes. This will provide you with an all-wood, dry floor on top of which you can put carpet or whatever else.

Again, it all comes down to your individual needs. There are many options, and it’s up to you to weigh the pros and cons of each. At the end of the day, just remember that the more money you spend upfront, the better insulated your basement will likely be.