(03-23-2012, 02:24 PM)GP-CA Wrote: It seems that this topic is only directed to an above level concrete slab w/pan? It is somewhat silly to even do an RH reading of this type slab. Moisture levels in these above level cement poured substrates will continently fluxuate to unknown severities depending on what is happening environmentally below. To try to find a liquid application of a vapor barrier, based on the maximum tolerances of any product is ludicrous. All above crete type slabs must be sealed with a barrier which should meet or exceed the permeation rating of the 6mil plastic sheet. That of lesser perm value is rather a gamble in any sense.
Moisture levels will fluctuate to unknown severities?
That is not the case in a climate controlled structure, which is where we place 99% of our flooring. We control temperature and humidity in our buildings which in turn results in predictable and calculable moisture levels in suspended concrete slabs.
While extreme fluctuations in temperature can impact RH readings, the moisture levels are much more consistent and slow moving. Proper application of RH testing will result in accurate and dependable RH readings which can be used to determine the suitability of the concrete for floor covering.
Concrete Answers for Flooring Problems