musty smell from crawlspace entering home

Old 11-04-19, 04:55 AM
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musty smell from crawlspace entering home

My downstairs bathroom has a distinct musty smell because it has no insulation under the wood floor, which sits 1 foot above exposed dirt in the crawlspace.

My upstate New York 1935 home, was built on a slope. The enclosed crawlspace, which ranges in height from 1' to 5 ' has a rock wall perimiter and exposed dirt floor. It is powder dry. I recently had a company do closed cell spray foam insulation under the floor, but because a few areas only have 1' height, the spray foam technician was not able to attain full coverage. He got 95% of the floor (crawlspace ceiling) covered, but the underside of the bathroom remains partly uninsulated. There's no way to get in there from underneath.

When you're in the bathroom you feel a slight draft coming from below and a musty smell that spreads throughout the house..

What can I do to eliminate the smell? The floor has two layers of wood right now. The original 1935 base floor (planks) and then, on top of that, a tongue and groove engineered wood flooring. Would inserting a vinyl material between the base floor and the engineered wood flooring be a solution or an invitation for rot?

Any other ideas?
Old 11-04-19, 05:35 AM
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My first step would be to seal up any gaps to the crawl space. Usual culprits are where pipes and wires penetrate. Some spray foam could take care of it pretty quickly and easily.

You might also be getting drafts where the walls meet the floor so you might caulk the baseboard. You can also get foam insulation for outlets and switches to stop drafts coming through them.
Old 11-06-19, 01:44 AM
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I'd be covering the dirt with poly and making sure the vents are open to the outside so the space is breathing.

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