Glossary: Flooring Adhesive

Glued down hardwood floor: Thinset mortar and trowel
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Other Names: Flooring Glue, Floor Adhesive, Carpet Tape, Carpet Glue, Carpet Adhesive

Flooring adhesive refers to any of a variety of solutions which are used to install a floor surface covering material to the subfloor or underlayment. Different types of adhesive are recommended for different types of flooring, although some multi-purpose solutions can be used effectively with multiple materials. You should always follow all of the manufacturer's recommended instructions.  

The following are important considerations when choosing a flooring adhesive for your project. This information should be available in the product specification sheet.

Substrates: Certain adhesives will bond better to different types of subflooring. Damp below grade concrete will require a different bonding material than flooring installed on dry at-grade concrete. Some of these adhesives can also be used to install on plywood sheets, though there are specific hardwood bonding agents as well. You may also need a specialty adhesive if radiant heating is being installed.

Location: Interior installations are generally not subject to large amounts of weathering and water damage. If you are going to be installing in an exterior environment then you will need a flooring adhesive that can handle the stress of rain, sun, snow, and cold. Climate also plays a role as some adhesives will do better in warm humid areas, while others are formulated to withstand freezing temperatures.

Recommend For: This is a term that you will often find on adhesive packaging and instructions. It refers to what the product is specifically to be used for as far as material, substrate, and environment. In some cases, this will be followed by the term “but can be used for” which refers to situations where the product can work, but might not be as effective as other solutions.

Ecological Factors With Flooring Adhesives: Volatile Organic Chemicals, sometimes referred to as V.O.C.’s, are toxic materials which are sometimes off-gassed from certain chemical flooring adhesives. These particles can be harmful to the indoor air quality of a space and can exacerbate asthma and other respiratory problems. Purchasing high-quality adhesives from reputable manufacturers should help to avoid this problem.

Self Adhesive Tiles: Some types of resilient flooring such as vinyl, cork, and linoleum tiles will be self-adhesive backed. That means that installation simply requires the peeling off of a protective paper layer to reveal adhesive already in place. The tile can then be pressed into place without the requirement of any additional substances.

Types Of Flooring Adhesive

Polyurethane Based: These are the most common and popular flooring adhesives available. Solid form, they do not evaporate away into the air, but instead, form a solid rubber structure between the bottom of the surface and the top of the subfloor. These adhesives have been around for years and their durable properties are well understood.

Water Based: These adhesives are generally lower in VOC content and are therefore slightly better for both the interior and overall environment. At the same time, they are much easier and less of a hassle to clean up. The drawback is that if there is too much moisture in the substrate you could end up with a loose, weak bond.

Carpet Adhesive: Many carpets are affixed to the padded under bed using adhesives, or double sided carpet tape. In some cases, these can contribute negatively to the indoor air quality of the space. However carpet manufacturers now also offer low VOC off-gassing carpet adhesive options.

Flooring Adhesive Considerations

How Fast Does It Dry: This will be important for the rate of which you will have to work, and the amount of adhesive you will have to prepare at each stage. It also determines how long you will have to wait before you can actually walk on the surface of the floor without having to worry about the materials moving.

Consistency: This refers to how well the adhesive grips to the trowel or tool being used, and how easy it is to spread it out across the subfloor. Too thin and the material will wash out making it difficult to work with. At the same time, an overly thick consistency can be very hard to spread.

Coverage: When deciding how much adhesive you will need for a flooring installation project you should consider the size of the space, and then add ten percent to that for waste. Most adhesive packaging will clearly state how large an area it is estimated to be able to cover.

Shelf Life: Depending on when the project takes place you may have to consider shelf life. Some adhesives can be stored for years and used without any degradation of quality. These can be kept in stock in case you need to perform repairs. However, some chemical adhesives will have a relatively short shelf life with their ability to bond diminishing over time.

Clean Up: The adhesives used in a flooring installation project can be some of the most difficult things to clean up and remove from surfaces. In general, water-based glues will be easier to get clean, but that will also make them susceptible to water degradation.

Flooring Adhesive Precautions

You should always follow all of the manufacturer's instructions when using a flooring adhesive. The adhesive used should be specifically noted as being appropriate for the material, substrate, and environment. Make sure the area is always well ventilated, and with toxic materials use fans and masks to protect the health of your lungs. Goggles and gloves are also recommended to protect your skin and eyes.

Flooring Adhesive Tools

Trowel: A notched tool that is generally used with mortar based adhesives. The notches allow you to create grooves in the glue mix, which help to grip the flooring material being pressed into place.

Rollers: These are round tools which are rolled across flooring adhesive, often carpet glue, in order to ensure a smooth, flat, even surface that is free of bubbles.

Mallet: A rubber mallet is used when installing hard tiles, in order to firmly press each piece down into the mortar bed below.