NO-94-19-4 -- Crawl Space Moisture Conditions in New and Existing Northwest Homes PDF

Crawl spaces of numerous homes were inspected during winter for moisture problems in the north-west of the USA. Some of the older homes did not have a ground cover in the crawl space, and standing water was noted in some of the crawl spaces with and without ground cover. Both open and closed vents were observed, though open vents were the most common. Mould and mildew in the form of very minor surface staining were only occasionally observed in the crawl spaces, and generally there were no noticeable musty odours. No wood decay was observed, except in a very few cases. Generally, the crawl spaces were almost completely devoid of moisture-related problems. Possible reasons for this are explored, as are code ramifications. Differences in moisture conditions in northwestern and southeastern US crawl spaces are discussed.

KEYWORDS: crawl spaces, moisture, USA, dwellings, winter.