Your Place: To seal or not to seal, that is the basement question

Ernie Wyatt, who is from near Macon, Ga., sends the following question:

"I have discovered that water has been standing in a corner of my basement in a crawl space and there is a bit of mildew in the area.

"A contractor has informed me that a permanent solution to the problem would be to treat the mildew and then haul in some sand, level the crawl space, and encapsulate the basement, sealing it from the outside.

"I have heard, however, that encapsulation can promote dry rot. Would it be wise to leave some of the vents open?"

Over the years I've written this column, there has been a huge debate over whether or not to open or close the vents.

In the winter, the question generates as much controversy as whether or not to cover your central air-conditioning unit.

By the way, the breakdown of cover vs. non-cover is 50-50. My neighbors and I do not, but my advice is to check with either the installer or the manufacturer for what is right for your unit.

Vents are installed to meet local building codes, but some builders have told me that they don't really work as intended.

I keep mine closed year-round and my crawl space, which is concrete, unlike most, is as dry as a bone.

For an answer to your problem, I went to the website of the Virginia-based GCI Energy Consultants.

I chose Virginia because of its high humidity levels, which are more like Georgia than interior South Jersey.

"For areas like ours where the humidity levels are so high, vented crawl spaces are a recipe for disaster," the GCI Energy expert wrote.

"In the summertime, very warm and moist air on the outside of your house is attracted through the open vents in your crawl space because we know that hot goes to cold," he said.

"The best solution is to completely seal your crawl space and do away with the problem completely," he said.

"Because moist crawl spaces cause the humidity in your house to rise, which makes you uncomfortable and makes your HVAC work harder costing you more money," he said.

I hope this helps.

aheavens@phillynews.com or write him at Box 8263, Philadelphia 19101. Volume prohibits individual replies.