12 CONCRETE REPAIR BULLETIN JANUARY/FEBRUARY 2006 Concrete Slab Repair: Getting Flat is One Thing, Staying Flat is Another!

Constructing concrete slabs to successfully receive moisture-sensitive flooring materials or coatings is not a simple process. In today’s market, fast-track construction has shortened the time period provided for concrete slab drying which, along with several other factors, has led to a significant increase in moisture-related flooring problems nationwide. Steps should be taken during the design phase of a project to minimize the potential for moisture-related issues. Such steps include, among others, the requirement for a low-permeance puncture-resistant vapor retarder directly beneath the slab to minimize moisture vapor transmission from the underlying base (Craig 2004), using moderately low water-cement ratio concrete mixtures (Kanare 2005), and allowing an adequate drying period or includin