Humidity in Basement
chris8251
| Posted in General Questions on
Last year we added an addition onto our house located in Nova Scotia on the Bay of Fundy.The foundation is ICF and the header spaces are insulated with spray foam. There is drainage tile around the outside of the foundation. The problem – I’m getting around 4gal of water a day from my dehumidifier in the crawl space! (unheated). The floor of the crawl space is earth/sand/PLASTIC/Sand. There is no standing water and no signs of leakage but the top layer of sand is wet in some areas. There is no ventilation in the crawl space. Any ideas on how I can remedy this? I can provide additional info if required
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Replies
Chris,
This problem is hard to diagnose without a site visit.
Is the crawl space under the addition open to the foundation (basement or crawl space) of the older section of the house? If so, the moisture you are collecting might be originating from the area under the older section.
Another possibility: there is a high water table in the soil under your house.
A good sealed crawl space requires attention to detail. Here's an article that tells you how to do it: Building an Unvented Crawl Space.
Martin
Thanks for the information and very helpful link. There is no linkage to the old basement and it is nice and dry - Its dehumidifier only runs periodically. A high water table is the possible primary cause as this area was wet prior to building the addition. The foundation contractor said the foundation drainage would handle this. (He hasn't been helpful with the current problem - typical!:( ). I'm going to check some things out in the space this week.