Build Your Own House

Crawl Space Vents and Ventilation

Summary: Crawl space vents provide crawl space ventilation that will help prevent mildew and rot. Crawl spaces can collect water vapor and condensation.

Carl, We have been in our new home 14 months and currently have a problem with crawlspace condensation.

We live in North Carolina and it has been extremely hot and humid this summer.

We are gathering information on conditioning our crawlspace and wondered if you had an opinion on homeowners doing this themselves.

Also, if you have any reputable product links... they would be greatly appreciated.

We have been amazed at what these businesses are charging for their services and thought we may be in the wrong line of work.

Thanks ahead for any input you can offer!

Sincerely, Ann and Jason

Hi Ann and Jason,

Crawl space condensation is a common problem…and a serious one.

Proper ventilation of the crawl space is important.

Crawl spaces are a source of moisture in a home providing an environment for mold, fungi, and insects that destroy wood framing.

I have seen crawl spaces when I lived in North Carolina (non coastal) that were solid mold and mildew due to humidity after just a short time.

This is not only a health hazard but a structural problem too (rot). It is also a magnet for termites.

I’m not sure what “businesses” you are referring to that seem to be charging too much, but if I were you, I would first try to improve the ventilation of your crawl space with a crawl space power ventilator to see if that doesn't solve the problem.

With a crawl space power ventilator, ventilation can be initiated to decrease or increase crawlspace relative humidity.


Smart Vent Crawl Space Ventilator

Other than the wiring, a homeowner should be able to handle the job of adding a crawl space power vent and the expense should not be too great. NOTE: A vapor barrier covering the ground in the crawl space is also necessary.

Read this article from the National Association of Home Builders on:

Crawlspace Ventilation Systems - Manage crawlspace moisture with mechanical ventilation dehumidification.

If your problem persists, please let me know. Good luck, Carl Heldmann