Summer is a good time to go somewhere cool and dark. No, not the movies. This place is right under your feet — the crawlspace beneath your house. No homeowner likes to go there. Once in, we have to belly-crawl without bumping our heads on pipes and floor joists. Regardless, making the right changes down there can make a big difference in your energy costs.
“Warm weather is a great time to assess crawlspaces,” said DuWayne Dunham, energy services supervisor and lead energy counselor for Clark Public Utilities. “Checking them gives our customers the opportunity to fix or insulate them. If they need help, customers can check out our insulation and weatherization rebate programs.”
While the building industry moves toward tightening and conditioning homes and crawlspaces, Clark County requires ventilated crawlspaces. One reason is our county has high levels of radon in the soil. Radon is a colorless, odorless gas emitted by soils rich in granite. As radon decays, it emits atomic particles that damage cells. Today, radon is the top cause of lung cancer in nonsmokers.
There’s no safe level of radon according to the EPA, which suggests taking action to drop indoor radon levels when readings are above two picocuries per liter of air (pCi/L). These particles can seep through concrete in basements making them more hazardous than crawlspaces.
“Testing for radon is inexpensive and the large box stores all carry easy-to-use testers,” said Dunham.
You can slow the radon build up in the crawlspace by laying down plastic sheets, overlapping them, and putting them up the crawlspace foundation12 inches.
It’s a good idea to check your crawlspace every other year to answer these questions: Does the plastic on the ground still overlap? Does it extend a foot up the foundation? Is the insulation sagging? Has the insulation on the pipes come unwrapped? If you answer “yes” to these checks, fix them before winter.
During your belly crawl, did you find insulation under your floor and around your water pipes? If not, take advantage of Clark Public Utilities insulation and weatherization programs for electrically-heated homes to remedy that. Dunham explained that putting insulation under the floor, placing overlapping plastic on the dirt, and wrapping water pipes with foam improve the energy efficiency of a house.
Vents in crawlspaces have long been misunderstood. Years back experts advised that closing them during the winter to save energy. When your floor is insulated, and you have plastic down, there’s no savings. In our area, closing off vents in crawlspaces and basements can trap radon under the home.
“Insulating the floor and putting plastic down in a crawlspace helps the air circulate through the vents,” Dunham said. “Closing crawlspace vents shuts off the air flow and traps moisture.”
So, keep your crawlspace vents open year-round to stop radon buildup and keep the air flowing. To stop rodents, raccoons and other furry beasts from getting in, place screens or hardware cloth over the vents.
Sometimes you’ll find a cable installer or contractor has cut a hole in a vent screen to push a pipe or cable through. “Check the screens over your vents for holes and replace damaged ones,” Dunham said.
Leaks, moisture or standing water beneath your home are other things you should look for. Moisture there can damage the wooden foundation of your home and breed toxic mold.
“If you store belongings in the crawlspace, check them for moisture, mold, and critter damage too,” Dunham said. “Any issues you find — fix them now when the weather is nice, and your home will be ready to go in the winter.”
Energy Adviser is written by Clark Public Utilities. Send questions to ecod@clarkpud.com or to Energy Adviser, c/o Clark Public Utilities, P.O. Box 8900, Vancouver, WA 98668.
