Saito shares, ‘Manual crawl space vents, which are usually $15 to $25 per unit, run lower than the automatic crawl space vents like this Master Flow Automatic Foundation Vent from Home Depot, ...

The International Building Code requires vented crawlspaces to have one square foot of ventilation per 150 square feet of crawl space area to obtain a 1/150 net free ventilation area, or NFVA.

The "crawl" space is 5 feet in height (measured from the 4 inch cement slab to the top of the floor joists) and is 1100 square feet.... Q. I have just built a cottage on a lake in Northern Michigan.

Q: You have often said that crawl-space vents need to be opened in the winter. Why is that? I always thought they should be closed to keep my water pipes from freezing. A. I used to think the same ...

“Take a house with a vented crawl space and plop it down in Colorado. A vented crawl space will work perfectly fine because they’re not battling outdoor humidity like we are here,” he says.

Q. Our house is built over a shallow crawl space with vents. The space has a dirt floor and the ground is damp. There are no ducts or pipes in the space. Can we close the vents in winter?

Q. We have a crawl space under the front of our house that, to our horror, had become a rat condo, unbeknownst to us until the odor of urine began to permeate the living space above. (We had not ...

A sealed crawl space is better than a vented crawl space in controlling moisture and deterring pests. However, these were not common until 15 years ago and are rare.

The "crawl" space is 5 feet in height ... A. Current building code says that crawl spaces need ventilation at the rate of 1 square foot of net free vent area to 150 square feet of crawl space.

Q. We have a crawl space under the front of our house that, to our horror, had become a rat condo, unbeknownst to us until the odor of urine began to permeate the living space above. (We had not ...