AboutLen Kroll Expertise I can provide advice on the proper design, construction, maintenance, restoration, preservation, cleaning and waterproofing of log homes. Questions concerning proper cleaning, sealing, staining and waterproofing are within my area of expertise. My expertise includes new construction and existing log structures. Chinking application or restoration, log replacement and repair are also in my area of expertise.
Question I have discover that I have a crawl space moisture problem and it is a big one. Our home was build in the 70s and has 1/4 plywood over the joists and then 3/4 particle board layed down after the walls were installed. There have been a few water leaks here and there that lead to the particle board being removed from the kitchen and bathrooms. We had vinyl put down in the den and hall so we replaced the particle there so the glue would stick. Last year I put down laminate flooring with a moisture barrier in two of the bedrooms. They started to buckle with waves in them. I thought I had not left enough space for it to contract and expand. Boy was I wrong. When I started to repair it, the particle board under it looked like someone sprayed it with a water hose. VERY wet. Moldy too. I am sure that the floor under the vinyl is wet to but it is plywood and hasn't buckled. I think I have a handle on how to fix the crawl space moisture problem with a barrier and a dehumidifier. But my question do I need to take up the vinyl and the plywood under it or will it and the subfloor and the joists all dry out? And why didn't the particle board in the other rooms become damaged? Did the carpet let it breath enough not to trap the moisture? Thank you for you time and hope to hear from you soon. Robin
Answer Robin,
I can't be sure why some particle board buckled and some didn't. It is possible, as you suggest, the carpet allowed vapors to pass through and not soak the boards. It is also possible that the plywood under the vinyl is not wet because the layers of glue in the plywood prevented vapors from passing through to the bottom of the vinyl. If you can you might try to determine if the plywood is wet from the bottom side in the crawl space. If you can't maybe you can pull up a small section of vinyl in an area you can repair without cosmetic damage.
It is possible that if you really dry out the crawl space that the joists and sheathing will dry out, but I wouldn't count on it.
The most important thing is that you control the moisture; if you successfully do that there will be no future problem. Be sure that you use a vapor BARRIER not a vapor RETARDER in the crawl space and run it up the walls at least 6" and tape it to the walls. It is estimated that as much as 40% of the moisture in the living space gets there from the crawl space. If you control that moisture you have gone a long way in preventing problems related to moisture from occuring anywhere inside the living space. Good luck.
