Here's some references for vapor passing through concrete.
http://www.moxie-intl.com/tutorial.htm Waterproof - Waterproof concrete is impervious or unaffected by the liquid form of water. It will prevent the penetration of water. The term "waterproof" is frequently used inaccurately in the flooring industry. Waterproof concrete or waterproofing concrete does not stop water vapor movement. Concrete must be "vaporproof" before you apply flooring materials and/or surface coatings.
Vaporproof - Vaporproof concrete restricts or prevents the passage of water vapor. Waterproof concrete is not necessarily vaporproof but vaporproof concrete is always waterproof.
Water Vapor - Water vapor moves much faster and much more readily through concrete than water. Water vapor moves through the capillaries of the concrete left behind in the concrete making process (curing). Waterproof concrete does not stop water vapor. Water will not move through waterproof concrete, however water vapor will. Additionally, when water vapor reaches the dew point under flooring materials it condenses becoming water. This is extremely undesirable because the water will deteriorate the flooring adhesive or perhaps the flooring itself. Therefore, to waterproof concrete is not the issue with regard to the installation of flooring materials. The issue is to make concrete vapor proof. When you do it will be inherently waterproof.
Corps of Engineers Specification CRD-C 48 "Method of Test for Water Permeability of Concrete