Friday, December 3, 2021
Dec. 3, 2021

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Energy Adviser: Crawl space key to home’s comfort


The average homeowner probably never inspects their crawl spaces, and for good reason. The name itself is practically an invitation to discomfort, allergens and a bout with claustrophobia.

But anyone who’s ever signed a mortgage knows homeownership isn’t always cool beverages on the back porch — sometimes you have to get on your hands and knees and get a little dirty to ensure a home stays warm, dry and comfortable. So, this summer, take an up-close look at the space beneath your feet.

“When there’s an issue in the crawl space, the homeowner may not know about it until it’s a serious problem affecting other areas such as the floors, plumbing or causing high heating or cooling bills— just to name a few” said Energy Services Supervisor DuWayne Dunham. “But you can catch issues early if you add the crawl space on your annual home inspection to-do list.”

Crawl spaces are popular in Southwest Washington. They’re more cost-effective to build than basements, make plumbing and heating systems accessible and they leave room for floor insulation.

Perhaps the most important function of crawl spaces is the airflow they allow. The Pacific Northwest is notoriously soggy for more than half of the year. When that rainfall soaks in the ground, it wants to permeate the dirt under your home. If it becomes trapped there it can cause mold and rot issues in the wood and insulation beneath your floor.

But the vents around your foundation protect your investment by allowing air to constantly move through and carry the moisture where it should be — outside. So, look at the vents first. Make sure they’re not blocked. If they are, clear the obstruction. Then make sure the screens are in good condition so animals can’t get in.

“Decades ago, crawl spaces weren’t insulated so people kept the house warm by blocking their foundation vents in the winter,” Dunham said. “In those days it was a practical solution, but today it’s a bad idea. There’s still a ton of homes around Clark County with blocked vents. Those folks should open them up and let the house breathe.”

After you’re finished outside, grab a flashlight and crawl in. Look at the plastic on the ground. That’s your vapor barrier. Make sure it covers the dirt entirely. If you have to, move it around or add some later.

Homes built in the last few decades should have at least R-19 insulation in the floors, but the thicker the better. When you’re inspecting yours, look for any deterioration or damage. Be on the lookout for insulation gaps — especially where plumbing, electrical or ducting enters the floor. Fill in any you see. Even small gaps can make a room feel cold and drafty in the winter or unusually warm in the summer, and allow bugs inside.

“Insulation is one of the most cost-effective energy-savers you can put in your home,” Dunham said. “It makes a big difference all year long. The utility even offers incentives to make insulation projects more affordable for our customers with electrically heated homes.”

If possible, inspect the wood beneath your floors. Check for any rot or damage. If you spot some, it may be time to call a contractor. If your home has a radon mitigation system, make sure it’s in good condition as well.

On the way out of the crawl space, look at the access door and make sure it’s insulated, weather stripped and fits in place with a tight seal.

For information about crawl spaces and prioritizing energy efficiency projects, call the Clark Public Utilities energy counselor of the day anytime during business hours at 360-992-3355.

Energy Adviser is written by Clark Public Utilities. Send questions to or to Energy Adviser, c/o Clark Public Utilities, P.O. Box 8900, Vancouver, WA 98668.