Open-cell versus closed-cell spray foam
mariab2512
| Posted in General Questions on
My house is 7 years old, it’s all crawl space underneath the house. They sprayed open-cell instead of closed-cell, which I did not know.
They did a good job, but i was told by heating guys a few years ago that i should take it out and put closed cell. My hardwood floors are cupping just a bit, not much, in certain areas.
Is it OK to have open cell? I’m going to sell my home in a few months and will that affect the sale? Or is it OK?
thanks
maria brittis
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Replies
Maria,
We need some more information.
1. What is your climate zone or your location?
2. Where was the spray foam installed -- on your crawl space walls or between your floor joists?
3. Is your crawl spaced vented or sealed?
4. Does your crawl space have polyethylene installed on top of the dirt floor?
If your hardwood floor is cupping, it sounds like it is possible that moisture is migrating from your crawl space to your subfloor, which wouldn't be good. But we need to know more information to understand what is going on.
we live in south carolina
the foan was sprayed on the crawl space walls and i dont know if it was on the joists
the crawl space is vented
on top of the dirt floor is plastic
thanks maria
Maria,
I don't think your problem has anything to do with the use of open-cell spray foam. I think your problem is due to the fact that you have a vented crawl space instead of a sealed crawl space.
During the summer, crawl space vents allow warm, humid outdoor air to enter your crawl space. That raises the humidity level in the crawl space. Now that your crawl space is damp, so is your subfloor. The humidity in your floor system is making your flooring cup.
The solution is to seal your crawl space vents and to perform all of the modifications necessary to have a properly detailed sealed crawl space. Here is an article that explains what you need to do:
Building an Unvented Crawl Space.
Once your crawl space is sealed (not before), it may be useful to run a dehumidifier in your crawl space for 4 to 6 months until the crawl space and your floor assembly dries out. Once that happens, you can probably unplug the dehumidifier.