Description: Unwanted moisture in concrete floors causes millions of dollars in damage to buildings annually in the United States. Problems from excessive moisture include deterioration and debonding of floor coverings, trip-and-fall hazards, microbial growth leading to reduced indoor air quality, staining and deterioration of building finishes. Understanding moisture in concrete leads to design of floors and flooring systems that provide excellent service for many years. This book discusses sources of moisture, drying of concrete, methods of measuring moisture, construction practices, specifications, and responsibilities for successful floor projects.

Abstract: We work, play, shop, and dine on concrete floors every day. They are often covered with finishes ranging from spectacular to merely pedestrian, but we rely on the implicit understanding that they are doing their duty as platforms for our activities with little or no change in the substrate itself. Nothing could be further from the truth. Concrete is born of water, stone and cement. Without water, we simply would not have concrete floors. Yet unrestrained moisture can lead to failures of floor finishes, reduced indoor air quality, and hazards to movement of people, goods, and equipment.

The purpose of this book is to explain how to control moisture in concrete floors so that they can provide years of reliable service with minimal costs for maintenance and repair. Unfortunately, such expenses have become very large in recent decades. It is much easier and more cost-effective to keep a floor dry through proper design, material selection, and construction practice, than to dry a wet floor after a building is occupied. Newer materials and construction equipment make it possible for smaller crews to place larger floors with great efficiency. New methods of measuring moisture in concrete using relative humidity probes hold the promise of better understanding and prediction of moisture trends in floors. However, the rapid pace of construction and pressures to reduce construction costs can impede delivery of high-quality, long-term dry floors. Two fundamental concepts permeate this writing: the floor is part of a building envelope, but also is in itself a system comprising of many elements. For a floor to function successfully, specifiers, builders, owners, and finish flooring installers all must understand the factors for floor performance, especially moisture. 164 pp.