(11-06-2011, 06:19 PM)Rubensgt40 Wrote: Some guys put down plastic sheeting, then plywood, then overlay timber flooring. Is this a reliable mitigation against slab moisture?
Yes it can be, I do that all the time for floating floors. But if I am using a solid timber or the slab is below grade I take it a step further and use something like Bostik MVP4 first, then the plastic, then plywood and then 15lb roofing felt and finally the timber.
I have also tested these systems before hand using the Rapid Rh, and even going so far as to do a few F 1869 tests on top of the MVP4, even though the ASTM guru's say you cannot do that. Not sure why because if you take a close look at ASTM E 96 they use a dessicant to evaluate the product they are testing, and that dessicant is.....calcium chloride. Kinda confusing huh? Whats more confusing is that many of these people who frown on the old F 1869 test will always refer to the ASTM E 96.