Handling slab moisture under hardwood floors
Our 1960s colonial was built in a low lying area that gets very wet 4-5 months of the year. It has a slab on grade foundation with no signs of a vapor barrier having been installed at construction. The result is incredibly high humidity rates – often in the 70-80% range throughout the house. If left unattended, moisture can build up in areas like the brick entry way with noticeable dampness.
What options should we investigate to better handle the moisture? Seal the underlying slab? Install a vapor barrier? Some other option?
-Border of climate zones 5A-6A in Southern NH, but humidity is notably higher than expected due to lot location, proximity to water, high water table, etc
-We monitor humidity and take precautions as needed (open windows on low humidity days, run dehumidifiers and mini split AC on high humidity days, etc)
-The majority of the house is slab on grade with no crawl space and very little room (1-3 few inches?) between wood floors and slab.
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