Water can wreak havoc on a floor and its impact may not be noticeable until it is too late. Fortunately, pressure-sensitive tape technology has the ability to provide moisture barrier properties that can protect the floor from unseen damage and provide other installation and aesthetic benefits.

While tape is versatile, portable and easy to use, it still is necessary to understand the adhesive qualities behind the tape because it’s the “stickiness” that plays a key role in its functionality. Not only does tape have to provide a barrier against water; it also has to stick under wet—and often humid—conditions.

Moisture coming onto the floor from above may be easier to detect, but moisture emanating from below a flooring structure may require delving into a sub-area to find its origin. An untreated crawl space under a home is a prime breeding ground for moisture. When not properly ventilated, no ground cover is present, or standing water is found in the crawl space, that moisture can cause water vapor to rise up through the subfloor and into the floor, causing floors to cup or warp.

Pressure-sensitive adhesive (PSA) properties depend on the surface chemistry of a substrate. According to PSTC member and Mactac Global marketing manager for industrial and medical tapes Janet Page, adhesives that take time to properly cure and/or dry can leave residual moisture behind. Once water enters the adhesive, it can act as a weakening agent and reduce adhesion.

Page explains it is important to determine the applications and conditions where tape is going to be applied. “Installers can use the tape as a water or moisture barrier more effectively by creating a water barrier at the foundation level, using proper insulation techniques such as a multi-layer plastic extrusion wrap that provides moisture protection and durability in unforgiving conditions.”

Always consider the tape’s chemistry. The two most common tapes used for waterproofing are butyl rubbers and acrylic tapes. Acrylic tapes are made from either water- or solvent-based adhesives. Acrylic tape provides a reliable seal and has a high level of cohesion. These tapes are known for their durability and work well when seaming vapor barriers and used for sealing house wraps. Acrylic polymers are well known for their excellent weatherability and can be used in harsh outdoor and indoor environments for years without degradation. Tape used for moisture barriers are made from a range of materials and thicknesses to fit virtually any performance criteria.

Butyl tape is developed using a synthetic rubber adhesive. These tapes are designed to be air impermeable, waterproof and insulating. Butyl tapes are ideal for seams, providing a water-tight bond for optimum sealing. These tapes can conform to irregular surfaces without degrading adhesion strength. Butyl tapes have a high initial tack and are more aggressive on contact. They can also bond to a wide variety of surfaces.

An important concept for all installers to keep in mind is that if the project calls for a true water barrier, special products are available that offer high performance. Ultimately, barriers are most effective if installed with all laps, seams, penetrations and terminations completely sealed. Following a tape manufacturer’s instructions will ensure the project is safe from water penetration for years to come.