Moisture Sensitive Adhesives and Flooring Adhesive Failures

ABSTRACT: Over the last decade, changes in environmental government regulations have necessitated the reformulation of many historically durable adhesives used in the application of flooring materials. The most popular flooring adhesives traditionally used solvents containing volatile organic com­pounds (VOCs), but government-prescribed regulations that limit or restrict VOCs resulted in dramatic changes to most traditional flooring adhesives. Adhesives with VOC-containing solvents were replaced with water-based or 100% solids adhesive formulations. While these new formulations may reduce the environmental impact of new flooring installations, new adhesives are less durable and more susceptible to moisture-related deterioration. Within the past ten years more moisture-related flooring failures have occurred as adhesive systems have switched away from the proven VOC – containing technology to a newer, low VOC-compliant technology. If the con­crete is not properly sealed or allowed to dry, the moisture inherent to con­crete substrates can break down, re-emulsify, and dissolve moisture – sensitive flooring adhesives. Consequentially, applied flooring materials can delaminate, buckle, blister, and crack. This paper will compare the composi­tion of newer moisture-sensitive flooring adhesives with that of their VOC – containing predecessors, and describe the properties of the adhesives that reduce overall durability. Case studies of flooring failures resulting from mois­ture-related deterioration of adhesives will be presented for various flooring materials including carpet tile, sheet vinyl, and vinyl composition tile flooring. Recommendations for repairing failed flooring and providing durable new flooring installations using moisture-sensitive adhesives will also be included.

KEYWORDS: adhesive, concrete, floor, VOCs, moisture

Introduction

Over the last few decades, widespread failures of many different floor finishes applied to concrete floor slabs have become more prevalent. Adhered flooring materials, such as sheet vinyl, vinyl composition tile, carpet, carpet tile, and rubber flooring frequently require repair or replacement early in their service life due to failures such as delamination, blistering, lifting, and cracking. Although there are many factors that contribute to the increase in adhered floor finish failures, a common thread in many of the failures is the durability of the adhesive material used to apply the floor finish to the concrete substrate. These durability issues can be traced back to changes in the flooring industry that began over twenty years ago.