Understanding the Importance of Substrate Surface Water Absorptivity for a Successful Flooring Installation
by Dean E. Craft, principal, ISE Logik Industries
Often referred to as substrate “porosity”, substrate surface water absorptivity refers to the ability of a flooring substrate surface to absorb liquid relatively quickly. To better conceptualize, imagine a concrete masonry unit (CMU) block. If you were to place a drop of water on that CMU, the water would absorb very quickly into the block. Now, imagine a hard, smooth surface such as steel, or existing resilient flooring, or power-troweled concrete; all of which could serve as the substrate for many different flooring products. If you were to place a drop of water on any one of those surfaces, that drop of water would basically sit there and likely evaporate before ever being absorbed.
Why is this of concern for a successful flooring installation? Before we attempt to address this question, it is helpful to provide some historical context. If we go back in time several decades, beginning in the 1970s and gaining significant momentum into and through the 1980s, there were growing concerns over indoor air quality; and, this eventually encompassed the flooring industry:
“On January 11, 1990, the National Federation of Federal Employees (NFFE), Local 2050, petitioned the EPA under section 21 of the Toxic Substance Control Act (TSCA), 15 U.S.C. 2620 to initiate rulemaking proceedings…to reduce emissions from new carpets.” (Federal Register, April 14, 1990, p. 17404).
While the EPA “…decided not to initiate the specific rulemaking proceedings …”, the EPA did decide to “… initiate a series of actions designed to assess and, if necessary, reduce the public’s exposure to compounds which may off-gas from carpeting.” (Federal Register, April 14, 1990, p. 17404) Upon mutual agreement with the EPA, the Carpet and Rug Institute (CRI) voluntarily agreed to conduct total volatile organic (TVOC) emission testing on various materials, and reported the results to the EPA’s Office of Toxic Substances in the “Carpet Policy Dialogue Compendium Report” (Sept. 27, 1991; p. 296).
Following closely on the heels of the Compendium Report, “… CRI launched its Green Label (1992) program to test carpet, cushions and adhesives to help specifiers identify products with very low emissions of Volatile Organic Compounds (VOCs).” (Green Label Plus: A Higher Standard for Indoor Air Quality; 2020). This resulted in a fundamental, rapid, and fairly radical change in the formulation of many of the adhesives and other constituent components used for flooring.
New vs. old
There is a common belief that the “good glues” of times past were insensitive to concrete substrate moisture. That is actually not the case and there is literature going back to the 1950s discussing this topic. Building on that misconception, many believe that the “newer water-based” adhesives are the primary source of flooring installation issues. Historically speaking, those “newer” glues are not really that new anymore; many of which began their evolution almost 30 years ago. Further, over that time, there have been untold millions of square feet of very successful installations. However, there is a fundamental difference between many of those older adhesives and many of the newer ones; especially in how they behave once applied to a substrate surface.
From time to time, in response to changing technologies, new ASTM standards related to flooring installation are published that may go unnoticed across the specification community. One such ASTM, F3191 Standard Practice for Field Determination of Substrate Water Absorption (Porosity) for Substrates to Receive Resilient Flooring, attempts to proactively identify just how an adhesive should be applied, and even what adhesive should be specified. read more…
Q: How did you become an expert in moisture mitigation in concrete?
A: In my 20+ years as a flooring claims investigator and my role since then as founder and principal of ISE Logik, I’ve encountered a lot of misconceptions about moisture and concrete. (In fact, some of these have been held by people you think would know better!) In our company, our business is to help everyone in the flooring and construction industry avoid the time consuming and costly impact of vapor transmission through concrete slabs with both our admixture formulas and topical coatings. Over time, moisture can simply ruin a beautiful flooring installation. So, we know all the ins and outs about moisture—we have too! read more…
By David P. Seland
Principal, ISE Logik Industries
Condensation occurs when air, saturated with water vapor, reaches a dew point temperature. When this temperature is reached, moisture forms on the surface of an object, resulting in what we know as condensation. read more…