Should I Vent My Crawl Space?

Building codes generally require working vents in the crawlspace to allow outside air to circulate under the floor in the summer to prevent moisture buildup that, among mildew and mold, encourages wood rot.

Should I keep my crawl space vents open or closed?

Your crawl space vents should always be closed and sealed off from the outside elements. ... First and foremost, open vents allow moisture to enter your crawl space. This creates the perfect environment for mold growth and mildew.

Is sealing your crawl space a good idea?

“Ok, but should I seal my crawl space?” you ask. Yes, you should. All crawl spaces should be completely sealed and isolated from moisture in the air and from the ground.