Skip to Main Content

Why Should I Insulate My Crawl Space?

Schedule Your Free Inspection

The crawl space is often the most neglected part of a home. I mean, why would anybody want to crawl around in a dark, damp space that is infested with spiders and other bugs? It turns out that neglecting your crawl space – or at least its insulation – can have a drastic effect on the energy efficiency of your home.

So, we encourage you to put on some old jeans and crawl around beneath your home. It might just lead to some discoveries that, when fixed, could lead to substantial energy savings! Here are the things you should be looking for:

  • CRAWL SPACE VENTS – Crawl space vents were originally designed to allow moisture out of your crawl space to prevent rotting of your floor joists and prevent mold from growing. As building science has progressed over the years, they found that this actually led to more problems. If your crawl space vents are open in the winter, the cold air enters under your home due to the stack effect. In the summer, it brings in hot, damp air that then rises through your home. In both cases, it means you are spending more to keep your home the right temperature.
  • GAPS BETWEEN FOUNDATION WALL AND FLOOR ABOVE – The spot where your foundation wall and the beams above it meet is called the sill plate. Often times, if there has been any foundation settlement or the sill plate shrinks due to the cold, a gap forms between the foundation wall and main beams. This allows air into your crawl space, causing the same problems as open crawl space vents.
  • INSULATION OF FOUNDATION WALL AND FLOORS ABOVE – Many crawl spaces are built without any insulation in them. When insulation is installed, it is most commonly found between the floor joists to prevent the crawl space air from entering through the floors above. Rarely do home builders insulate the foundation wall or sill plate. Even if they are insulated, the insulation tends to sag, droop, and stop working. How can it insulate your home above if it has fallen off? If you notice your insulation drooping, you likely have a moisture problem, but definitely have an insulation problem.

The crawl space is an important structural element of your home. It supports the weight of your home above it. And if moisture enters, it causes insulation and structural problems.

Don’t neglect your crawl space. If you want to protect your home and see drastic improvements in energy efficiency, you should go down there and check if your home has crawl space vents, any gaps at the sill plate, or insulation. Closed-cell spray foam is the ideal solution for insulating your crawl space. It is water impervious, fill every crack and gap, and will never sag like fiberglass or cellulose insulation commonly does.

Of course, if you don’t want to go down there or you find a problem, a professional at Peak Structural can look for you and let you know how to best insulate and protect your crawl space.

Publish Date:

Last Modified Date:


Colorado Springs Office

707 County Line Rd.
Palmer Lake, CO 80133

Denver Office

4686 Ivy St
Denver, CO 80216

Grand Junction Office

2575 U.S. 6 & 50, Unit A, Grand Junction, CO 81501