Protect concrete slabs and floors with a moisture barrier.
Your foundation is essential, but if it isn’t shielded from damp, what good is a sturdy foundation? The experts at ISI Building Products claim that remediating below slab water vapour after the fact is a difficult and expensive fix. According to them, selecting and correctly installing the right below slab water vapour protection is crucial for the finished floor as well as your general health and safety.
For under-slab water vapour retarders and barriers, industry organisations like the American Concrete Institute (ACI) and the American Society for Testing and Materials (ASTM) have developed particular recommendations and testing standards.
A testing standard used to assess a product’s performance is ASTM E 1745 (Standard Specification for Plastic Water Vapour Retarders Used in Contact with Soil or Granular Fill beneath Concrete Slabs). Materials are categorised according to ASTM E 1745 as A, B, or C depending on their tensile strength, water vapour permeance, and puncture resistance. The maximum tensile strength and puncture resistance are found in Class A vapour retarders and barriers, with Class C being on the lower end of the spectrum. For all three classifications, the water vapour permeance criterion is currently set at 0.1 perms, with puncture resistance and tensile strength serving as defining characteristics.