It is indicated in your publication that most floor construction is improved by including a vapor barrier. There are a number of experiences in our area that indicate the use of a vapor barrier may not be advisable. The water in a concrete slab placed on a vapor barrier has nowhere to go but to the top of the slab. Considerable cracking has resulted, which is felt would not have occurred if no vapor barrier had been used.
Vapor barriers are recommended where floor coverings, household goods or equipment must be protected from damage by moist floor conditions. Concrete in itself is not vapor-proof and waterproofing additions have not been found beneficial. It is fully recognized that the installation of vapor barriers requires special attention, but they should be used only where conditions at a particular site or for a particular performance require them.