I have a conventional 2x8 floor that is 40 inches off the ground. The crawlspace has 6"x12" vents on all sides of the house, spaced every 12-15 feet. We live in a humid area.
Can I add plastic moisture barrier under my conventional floors without further damaging wood floor joists?
Humidity is confusing. Too much can cause moisture on inside of windows, mold , etc. , too little can reduce moisture in wood and cause it to dry out and twist boards.
Here is an article that explains it:
https://www.coolray.com/help-guides/indoor_comfort_issues_to_much_or_too_little_humidity
You indicate you live in a high humidity area when you say, will adding a moisture barrier create “further damage to your wood joists”. Therefore, I’m not concerned about drying the wood out to the point it will twist and crack.
I don’t think venting is the answer. If you increase the venting, you are merely exchanging old humid air with new humid air.
A moisture barrier on the ground could trap extra moisture and create a place for bugs and mold.
I think a dehumidifier is a better choice than trapping moisture in the ground under your house, but you’ll need to monitor it closely so it doesn’t dry the joists out too much.
