A significant amount of time and effort goes into selecting the right commercial carpet for clients - marrying desired aesthetics with practical requirements - but the type of adhesive used is often overlooked in the decision-making process.
However, not all flooring adhesives are the same: they may have different tolerances for moisture, or react differently to other products used in the installation process. So, how do you select the best adhesive to suit your install requirements?
Today we're sharing five key aspects to look for when reviewing carpet tile adhesive.
1) How Long is the Warranty?
You might be surprised to discover that most adhesives come with a short 1- to 2-year warranty. Adhesive manufacturers offer a limited warranty to flooring manufacturers, which is typically then passed directly on to the customer. Doing so creates an interesting disconnect: your flooring product may come with a 15-year or lifetime warranty, while the adhesive holding the product in place is only warrantied for 1 to 2 years.
Some flooring manufacturers now go beyond the standard warranty and match their product warranties with an extended adhesive warranty - a good indication of their confidence in the long-term performance of their product.
2) Is the Adhesive Rated for High Moisture?
Moisture is becoming a concern on almost every installation, from renovations to new builds alike. All carpet tile adhesives have stated RH (relative humidity) and pH limits, and using the adhesive in conditions which exceed these limits puts you at risk of adhesive breakdown.
The RH and pH of a slab go hand in hand: if your slab has a high RH, the adhesive will need to be rated for a higher RH and pH to accommodate these conditions. A good rule of thumb for a high moisture adhesive is an RH of 95 and pH of 12.
Many installation instructions have very specific RH and pH limitations, so ensure your adhesive is within these limits before its time to install flooring.
3) What Installation Procedures are Required?
Different manufacturers will have various floor prep requirements to follow during installation. Failure to do so can void your warranty and impact the efficacy of your adhesive.
For example, some manufacturers require you to remove every trace of residual adhesive before beginning to install the new flooring. In real terms, this means either grinding away the traces of adhesive or sealing the floor - both of which significantly increase the install cost because of the additional labor and materials required.
However, the most rigorous floor prep is only required as a means to prevent chemical incompatibility between flooring products, or ensuring existing adhesive doesn’t telegraph through the back of thinner thermoplastic backings.
Compare floor prep requirements between different manufacturers before specifying flooring so that unexpected costs don't impact the project budget.
4) Is there a Risk of Chemical Incompatibility?
Most manufacturers require you to follow ASTM F-710 installation standards, which includes conducting standard tests, such as moisture and bond testing, and removing common concrete additives - like curing compounds - before installation.
There's good reason for this - chemicals and admixtures used on concrete can adversely react with flooring adhesive. These “bond breakers” cause flooring failure by preventing adhesive from functioning properly and include:
- Residual adhesive remover
- Abatement chemicals
- Curing agents on the concrete subfloor
To simplify the installation process, the best option is to look for non-reactive carpet tile adhesives - products that are chemically inert and have been specially designed to eliminate the risks of chemical incompatibility.
5) Adhesive vs. Adhesive-less Solutions
Many flooring manufacturers now offer adhesive-less solutions to avoid the need for adhesive altogether - even positioning them as their solution to high moisture slabs.
Adhesive-less products enable you to install carpet tiles without applying adhesive to the subfloor. Instead, you apply a tape, tab or sticky dot to the corner of each carpet tile, creating a “floating floor” that stays in place due to the overall weight of the connected flooring.
There are several limitations to adhesive-less solutions:
- If the product has a hard backing, there's a real risk of liquid water forming on the back of the tile, creating conditions conducive to mold and mildew growth.
- Some adhesive-less solutions still use an adhesive on the back of the tape or tab, which can fail in high moisture environments.
- Depending on the dimensional stability of the product, the center of the carpet tiles may not sit flush with the subfloor, and the flooring can be distorted by large rolling loads.
- Adhesive dots and tabs are very labor intensive to install. Each piece of tape needs to be peeled off and stuck down - which can amount to hundreds, if not thousands of pieces of tape over your floorplan.
If you're looking for an adhesive-free method, there are alternative solutions, such as TractionBack® from Milliken, which uses a high-friction coating to keep carpet tiles in place.
TractionBack® coats the entire back of the carpet tile, ensuring the whole carpet tile will contact the subfloor when installed. The coating is applied during manufacturing and doesn't require peeling off any backing, reducing waste from installations, improving indoor air quality with a bio-based solution and allowing for a space to be used immediately after carpet is installed.