During the course of this presentation, Jeff Johnson, will discuss the process of polymer coalescence and why that is important for high moisture resistant adhesive function. Understanding how water-based pressure sensitive adhesives work will allow the contractor to avoid certain conditions that may defeat the claims made on products like this. He will also discuss the chemistry of a concrete slab and what drives moisture movement - important  for the contractor to understand the science of concrete curing and what drives moisture through a concrete slab. He will also discuss topics including:  diffusion of moisture in a concrete slab, semipermeable membranes and how they are made in a concrete structure, the origin of soluble salts in concrete, their dissolution and precipitation on the surface (efflorescence) and how all of this drives moisture movement that can result in catastrophic floor failures. All of this is offered to better understand how floor installations fail in spite of claims made by adhesive and flooring manufacturers and why it is still critically important to make sure a concrete slab is isolated from the earth and an infinite moisture source.