How Do I Insulate My Crawl Space the Right Way?

As colder weather approaches, homes with crawl spaces often start to feel chilly, especially when the floors above are cold. If your crawl space isn’t insulated correctly, cold air can settle underneath your home and make living spaces uncomfortable.

Follow these important DOs and DON’Ts to help keep your crawl space warmer, drier, and more energy efficient.

DOs: What You Should Do to Insulate Your Crawl Space

DO Permanently Close Crawl Space Vents

Open crawl space vents allow cold outside air to flow freely into the space beneath your home. That air lingers under the floors and eventually seeps into the rooms above.

Sealing crawl space vents helps stop unwanted air movement and keeps cold air out where it belongs.
 

DO Insulate the Rim Joist

The rim joist is one of the most common sources of air leaks in a crawl space. Small gaps around the sill plate, pipes, and wiring allow cold air to enter easily.

Expandable spray foam is an effective way to seal these gaps and prevent heat loss, improving comfort throughout the home.
 

DO Keep Your Crawl Space Dry

Moisture and humidity are the biggest threats to a healthy crawl space. Even without visible water, moisture from the ground creates water vapor that clings to wood framing and encourages mold growth.

Encapsulation with a vapor barrier, along with proper drainage and dehumidification, helps control moisture and keeps the crawl space warmer year-round.

DON’Ts: Common Crawl Space Insulation Mistakes to Avoid

DON’T Insulate Between Floor Joists

Placing insulation between floor joists is a common mistake. Insulation should be installed along the air boundary surfaces, the crawl space walls and floors, and not between the living space and the crawl space.

The goal is to make the crawl space part of your home’s conditioned space by sealing it from outside air.
 

DON’T Use Fiberglass Insulation

Fiberglass insulation allows air to pass through it and loses effectiveness when exposed to moisture. A major issue in crawl spaces is the prevalence of humidity.

Rigid, moisture-resistant insulation materials designed for crawl spaces perform much better over time.

Get Help Insulating Your Crawl Space

Insulating a crawl space correctly requires more than adding insulation alone. Air sealing, moisture control, and proper materials all work together to protect your home.

Get a free estimate today to find out how crawl space insulation can help keep your floors warmer and your home more comfortable.