Understanding all components of a flooring system, as well as the immediate physical environment, is vital for the flooring installer. As the last contractor to be involved with the system, the installer is often the buck-stops-here individual who bears the responsibility for a finished flooring job that’s free of defects and problems. It’s a responsibility that goes beyond simply using a quality flooring adhesive.
It also involves the subfloor or substrate, the leveling and patching compounds, any moisture mitigation, such as a sealer and the flooring material itself.
“If the flooring contractor commences the installation without even questioning the condition of the substrate, the very act of commencing the installation constitutes acceptance in the eyes of the law, and he becomes responsible for the failure,” says Lew Migliore, president of Georgia-based LGM and Associates, which consults on floor covering complaints, problems and claims.
While it’s impossible for an installer to control all variables (Migliore cites an example of a vinyl installation that failed because boilers in a room below caused the floor to heat unevenly), there are essential steps an installer can take to help ensure a quality, trouble-free installation.
Surface preparation is not optional
No matter what the finish covering is, it all starts with substrate preparation. For example, a flat surface is essential for the installation of resilient flooring in order to minimize telegraphing, or the mirroring of substrate imperfections in the finish material. Depending on the specified floor covering (resilient, VCT, rubber flooring, large format tile or wood), tolerances may require a variance of as little as 1/16 inch in 10 feet. Patching compound or a self-leveling underlayment may be necessary to eliminate high and low spots and create an acceptable substrate for the specified floor covering.
Concrete slabs are particularly challenging when installing moisture-sensitive flooring, such as resilient. An installer should be aware of both the flooring and adhesive manufacturer’s moisture vapor emission rate (MVER) or relative humidity (RH) limitations. There are two industry-recognized quantitative tests: The calcium chloride test (ASTM F1869) expresses the vapor drive in a slab as pounds/square feet/24 hours, and the in-situ RH test (ASTM F2170) measures the percentage of RH within the slab at a prescribed depth.
Why is quantifying the MVER or RH in a slab important? Excessive moisture drive can destroy the adhesive’s bonding properties, causing it to emulsify, while the floor covering may stain or exhibit bubbles and blisters. If the MVER and RH exceed the manufacturer’s recommendations, it may be necessary to apply a moisture barrier to the concrete substrate before adhering the floor cover.
For renovations and replacement jobs, installers should be aware of what methods were used for removing old coverings and adhesives.
“We’re seeing more and more failures where there is abatement residue left on slabs, someone using a solvent that’s then washed off with a surfactant, both of which may affect the new adhesive,” says Migliore. Contacting the abatement contractor may be necessary to determine what methods were used to ensure correct preparation of the subfloor.
Check temperature and humidity
“Flooring and adhesive products have to be acclimated to the temperature of the room where you’re installing,” says Mark Jettenberg, owner of Affordable Floor Installation, “and wood products need to be acclimated to the humidity.” He should know. An installer with over 45 years of experience in the Minneapolis area, he’s dealt with his share of harsh weather. Inside temps shouldn’t be less than 55 degrees and the HVAC should be running. Jettenberg notes a particular problem with carpets that have been sitting overnight in a truck or garage. “You can’t lay them right away. Get them in, roll them out, and let them warm up,” he says.
Don’t assume you’ve seen it all
When it comes to choosing the right adhesive for the job, assumptions can be the enemy, even for highly experienced pros. That’s because flooring materials and adhesives are constantly undergoing revisions and technical improvements that alter their characteristics and requirements. It’s absolutely essential to read the installation recommendations from the flooring manufacturer and to understand the type of adhesive that’s best for the job.
Your best defense? “Pay attention to what’s recommended,” says Jettenberg.
- In general, high-quality adhesives with higher percentages of tackifier are better than lower-cost alternatives.
- Using the right trowel and allowing the correct open time for the adhesive are critical. Migliore notes that during the time it takes to install over a large concrete slab, friction can actually wear down a trowel’s notches, resulting in too little adhesive being applied.
- Read the technical bulletins and fact sheets from industry organizations, such as The Carpet and Rug Institute and Resilient Floor Covering Institute, to ground yourself in the latest improvements and notifications affecting adhesives and floor coverings.
Above all: “Take your time,” says Jettenberg. “Don’t be in a hurry.”
Be sure to join the Lowe’s ProServices LinkedIn Group to read additional content and interact with other Construction/Trade and MRO professionals.