Home>Discussions>HEALTH & SAFETY>Crawl space renovation will last or fail?
5 posts / 0 new
Last post
Crawl space renovation will last or fail?

Sounds like an oxymoron doesn't it? I recently looked at purchasing a house that is part of a revitalization effort in a small main street town. The house has a crawl space from 1900 era. Given most houses in this neighborhood (southern Indiana on the Ohio basin) have moldy, failing, substandard foundations, this one renovated well. The builder replaced any joists needed, installed a vapor barrier, new plumbing, everything in the house is new. No odors, no rot, no moisture, everything is up to modern standard. HVAC is located on the living floor and uses a trunkline through the attic. When viewing the crawl area via the little cellar created originally by the coal furnace, it was as fresh and neutral as any basement, if not more so.

My question is, given the organization spent well over 100K to renovate the house, can one not expect the crawl foundation to revert to its former state over time, ie. moldy, damp? The walls of the foundation are brick too = could wick moisture. Am I looking at the pinnacle moment of this house's future whereby it will go downhill from here? Crawl spaces are simply substandard by any measure and in any condition usually.

The builder sealed the six crawl space vents on this 1100 sf house. So there are no longer any vents. I'm suspicious of that too.

Re: Crawl space renovation will last or fail?

There should be cross ventilation in any crawl space, especially if the floor area is not concrete. Without proper venting the thousands of pounds of moisture coming up through the ground has no where to go but biologically attach itself to the organic dimensional lumber and feed the mold.

Rule of thumb is 1 sqft Net venting for every 200 sqft of crawlspace.

Hope this helps.

Re: Crawl space renovation will last or fail?

Usually when a crawl space is sealed, either the houses HVAC is ducted into the space or an dehumidifier is installed.

Re: Crawl space renovation will last or fail?

I agree. I think the contractor made a huge error by assuming this space would be "clean" although it clearly has never been so prior to the renovation. Still dirt under the vapor barrier.


Re: Crawl space renovation will last or fail?

I agree. The crawl space vents should be opened up if you want to keep moisture issues at bay. Working on old houses in Florida (very humid and wet) I rarely come across a properly vented crawl space with moisture issues.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.