There probably isn’t any part of the house where the old phrase “out of sight, out of mind” is more applicable than the crawlspace.
But crawlspaces are the unsung heroes of home construction. While homeowners are caught up in designing the perfect bathroom or matching their new appliances to the kitchen’s color palette, the crawlspace is beneath their feet, literally holding the whole place up, while helping occupants stay healthy — that is when the crawlspace is in good condition.
Crawlspaces are critical to a house’s structural integrity. Aside from creating a solid ground level for the house to be built on, a well-constructed crawlspace is crucial to helping a home be energy efficient, free of moisture issues and properly ventilated.
“People never think about the crawlspace until problems down there creep up through the floors and begin to affect the rest of the home,” Energy Services Supervisor DuWayne Dunham said. “When it gets to that point, they’ve got a real problem on their hands — which could have been much more manageable if it was caught early.”
Crawlspaces are common in Southwest Washington because they’re less expensive to build than basements or house-sized concrete slabs, they make plumbing and heating infrastructure easy to access, and because they allow critical airflow beneath the home.
Just like the rest of a home, crawlspaces need some occasional attention. That’s why you should make them part of your home inspection routine. You may get a little dirty in the process, but it won’t take long and you’ll have great peace of mind.
The inspection should start with the vapor barrier — a thick layer of plastic that should completely cover the ground. If it’s not, straighten it out or make a note of additions or adjustments that may be necessary. As the name implies, this layer is critical to preventing moisture from rising up through the ground and getting into your home.
Next look at the insulation between the floor joists. There should be at least r-19 insulation there, but thicker is better. Look for any deterioration or signs of animal damage. If the insulation is thin, missing or damaged, fix it right away. Insulating your floor will substantially improve a home’s indoor climate all year long, which will make the people inside more comfortable.
“Insulation is one of the most cost-effective energy-saving investments there is,” Dunham said. “Clark Public Utilities is so supportive of it as an energy-efficiency upgrade, we offer incentives to help make insulation projects more affordable for our customers living in electrically heated homes.”
Wherever possible, inspect the wood beneath your floor and at the perimeter of the home. Watch for rot, mold or animal damage.
If your home has a radon ventilation system, visually inspect that system to make sure it’s still in good condition.
Last, but never least, look at the crawlspace access. It should be adequately insulated, weatherstripped and have a tight seal when shut. Even small air leaks contribute to a significant amount of heat loss.
Finally, go outside and look at the vents. There should be some kind of screen over it, but nothing blocking it. Vents need to be unobstructed for the home to breathe and remove moisture and carcinogenic radon gas from under the home.
Plus, blocking the vents is also unnecessary in newer homes because insulated floors have been standard for decades.
For information about crawlspaces and prioritizing energy-efficiency projects around the home, call a Clark Public Utilities energy counselor anytime during business hours at 360-992-3355.
Energy Adviser is written by Clark Public Utilities. Send questions to firstname.lastname@example.org or to Energy Adviser, c/o Clark Public Utilities, P.O. Box 8900, Vancouver, WA 98668.