5 Important Things to Know When Insulating Your Crawl Space

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Few homeowners spend time in their crawl space, which is often relegated to being a storage space or as an accessibility solution to quickly reach into plumbing, electrical wiring, and heating and cooling components—if they’re used at all. Crawl spaces also play an important role in regulating indoor temperature and humidity levels, considering they are often a point of ingress and egress for heat, air, and moisture. 

In winter, they can get very cold and cause cold air to get into the house’s lower floors. In summer, they can get very hot and humid, in addition to becoming a magnet for mold and pests. These are some of the reasons why insulating your crawl space may seem like an extra chore that is quite insurmountable. But if you don’t insulate your crawl space properly, your overall indoor comfort—as well as your energy bills—may suffer for it. 

The rationale behind insulating your crawl space is making a proper thermal envelope around your home’s subterranean spaces. For one, it keeps air from escaping through the floor, if proper air sealing and installation of moisture barriers are implemented alongside the addition of insulation itself. For another, it preserves the structural integrity of your home’s floors and lower walls. You can control the amount of condensation that forms in and around them, and as a consequence, protect them better against mold growth and wood rot. Lastly, when you’re smart about your crawl space insulation, you end up not needing to use your heating or cooling appliances at their full power. This can lower the cost of your utility bills by a significant amount and keep your home more energy-efficient. 

That said, there are some considerations you need to make before buying insulation materials for your crawl space and having them installed. Here’s a checklist of sorts that will help you get the best out of your new crawl space insulation

Is Your Crawl Space Currently Ventilated or Unventilated?

One important factor to consider when insulating your crawl space properly is knowing whether it’s ventilated or unventilated. The so-called “old-school” crawl spaces are the type that are ventilated, i.e. outfitted with their own vents to allow outside air to circulate. Unventilated crawl spaces don’t have these vents or any additional ducts and pipes. 

Whether your crawl space is ventilated or unventilated determines whether you should insulate the subfloor under the crawl space or the crawl space’s walls. The general rule of thumb is to insulate the subfloor if the crawl space is already ventilated, ideally between the floor joists. If the crawl space isn’t ventilated, it’s both cheaper and more efficient to insulate the walls instead.  

What Materials Can You Use to Insulate Your Crawl Space? 

There are a lot of excellent crawl space insulation products out there in the market. You’ll have a lot to choose from once you hit the home depot or insulation store. Common insulation solutions for crawl spaces include fiberglass batts or rolls, rigid boards made out of polyisocyanurate, and spray foam insulation. 

Qualities you should look for in an insulation solution for your crawl space are appropriate R-value for your climate zone and additional moisture resistance in the form of a kraft paper or vinyl facing. Your supplier should be happy to take you through the differences between each product and help you decide which is best for your application. 

Do You Have Enough Space to Install New Crawl Space Insulation?

The next big question you have to answer is whether there’s enough wiggle room in your crawl space for you to install new insulation. This is a good time for you to clear any obstructions in the space, like Christmas decorations, unused furniture, or sports equipment if it is finished to serve as a storage space. You’ll also want to make sure there’s no unwanted moisture there, for example from puddles left by last week’s storm. 

Having a clean and neat crawl space will make installing new insulation so much easier. So, make sure that the ground’s cleared before you start.  

Are All Other Holes or Cavities in Your Crawl Space Properly Sealed Off?

Installing new insulation is your best bet towards regulating the temperature in your crawl space. But it’ll be for nothing if there are still gaps between the joists or cavities in the walls. There shouldn’t be any opportunity for air to leak out of your crawl space or for drafts to come inside. 

Part of the process of insulating your crawl space should involve caulking up very small holes and using foam sealant for larger ones. When you’re sure that air can’t come in or escape, you can start insulating your crawl space in earnest. 

Can You Insulate Your Crawl Space Yourself, or Do You Need Professional Help? 

When installing new insulation for your crawl space, you have two options: do it yourself or get a professional contractor to do it. If you have experience and you think it’s easy enough for you to do, you can definitely take charge of putting in the new insulation yourself. But the DIY approach doesn’t come so naturally to other homeowners, and if that’s the case for you, it’s totally fine to get professional help. 

Hiring a professional contractor is the best option for when the job is complicated and involves removing and replacing damaged insulation. It’s also a must to hire a contractor to handle certain insulation materials that need special equipment, like spray foam insulation, as well as other substances like fungicide. You can trust a contractor with the trickier insulation and repair work, which will also ensure that your new insulation solution will last. Ultimately, this saves you time, money, and grief over needing to switch out insulation very often. 

It may be a challenge to properly outfit your crawl space with new insulation, but the benefits to your health, comfort, and home spending are definitely worth it. A well-insulated crawl space means better energy efficiency and better indoor air quality and temperature regulation all throughout the home. Don’t delay the task of insulating your crawl space with new materials, and if needed, get some help to do the job properly!