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Options for sealing off basement crawlspace

479 Views 3 Replies 2 Participants Last post by  Nealtw
The "crawlspace"

In the back left upper corner of my basement, a hole was made to enable the addition of a powder room on the main floor 15+ years ago. The basement walls are concrete and the hole opening is not smooth nor square. The cavity enabled the installation of a duct, a drain, and cold and hot water lines, and electric.

Additional misc notes

- On the other side of the hole is a cinder-block sided cavern ~10 feet long, ~3 feet deep, ~3 feet wide. (see more pics below)
- I keep a small fan (pictured in the hole entry) on all year long to help air flow.
- I have a dehumidifier in the basement to keep the relative humidity down in the summertime to help prevent prevent mold growth.
- I also run an oransi air cleaner 24/7 about 8 feet from the corner.

The problem

In the winter, cold air sits in the cavern on the other side of the hole and there is a cold draft as a result. In the summertime, this area seems to be more musty smelling and the air coming from the hole seems more humid.

Can I seal it off?

I am looking for advice on how I might seal this off? Specifically, for example, I am wondering if I can seal this off with a vapor barrier and possibly insulation? Or perhaps there is another better approach?
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These spaces are always a problem, neither a basemen or a real crawl space.

If you don't have vents to outside it is part of the basement.
Do you have access to get into the space.
Thanks. No vents to the outside, and no access to the space.
What does this look like from the outside?
1 - 2 of 4 Posts
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