Crawl spaces
Should I Build on a Slab on Grade Foundation or a Crawl Space?
One of the first decisions when building a home is what type of foundations to sit your home on - cold-climates, termites, problem expansive clay soils, insulation & vapor &…
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If I crawlspace has water droplets forming under the poly vapor barrier (on the dirt side) that means that it is doing its job. Without the poly that moisture would have evaporated into the air, raising the relative humidity in your crawlspace and increasing your risk of mold forming. Here is our page all about how to insulate a crawl space –
Crawlspaces are very rare as part of a new home construction nowadays in USA & Canada. If you've got one here's how to fix it.
The condensation under your vapor barrier can be a little disconcerting to look at sometimes and it may seem like something is wrong, but that’s only because it’s see-through! if you had an opaque vapor barrier and you couldn’t see it you may be a bit more comfortable about it I imagine :-)
While it is working, if there is a lot of moisture its possible your home is sitting on ground with a pretty high water table, which is not a problem, but I would make sure that your vapor barrier is nicely intact. Does it go to the edges of the walls? Is it in good condition and taped at the seams? Its doing the right thing, so make sure it keeps doing it, that moisture is way better in the ground that in your home.
Thanks for your reply. The vapor barrier is overlapped, not tapped. I had high humidity which was causing mold growth. With the dehumidifier it varies between 50-55%. Mold growth has ceased.
Keep it to about 50-55% RH is good, that's about the high end you want to be at before mold becomes a problem again. Taping it woudn't be a bad idea, that may even drop it a little bit more, so will making sure it's sealed around the edge of the wall and any support post or plumbing pipes.
And if by chance you live in an area with high radon gas you might want to get it checked, you're a very quick fix to having a rudemendatry radon barrier and even radon evacuation stack. Not trying to find problems for you, but radon is still a bit unknown, and a very serious health concern. Here are our pages on it detecting and mitigating radon gas in homes.