By Barry Stone
Dear Barry,
When I bought my home, the inspector recommended that I keep the foundation vents open during the warm summer months and close them when winter weather turned cold. But then I read an article where you advised never closing the vents, regardless of weather conditions. Could you please clear up the confusion on this matter? -Mike
Dear Mike,
Homes with raised foundations are nearly always equipped with screened openings to provide cross ventilation of subfloor areas. Closing these vents is generally an unwise practice. The purpose of foundation vents has nothing to do with temperature control or energy conservation and is therefore unrelated to variations in weather. The primary purpose of foundation vents is prevention of moisture condensation on surfaces beneath the building. Therefore, open vents during wet winter months are essential. Closing your foundation vents during the winter is an invitation to condensation and resultant moisture damage, dryrot, and mold. Foundation vents should remain open at all times, especially during winter. Those who advise otherwise could be leading you down the path of costly structural repairs and possible health hazards.
An exception to this venting rule involves homes with perimeter insulated foundation systems, specifically engineered for energy conservation and provided with alternative means of moisture control. Such construction methods, however, are rare.
Copyright 2004-2006 Barry Stone. Distributed by Inman News.
. Questions of a Do It Yourself nature should be submitted our "