Glossary of Terms – Adhesive

Term Definition
A substance which is capable of holding materials together by surface attachment. 
Adhesive is also called cement, glue, mastic, and paste.
Adhesive Bleeding  Undesired migration of materials in the adhesive to the surface of the floor between seams.
Balling Up
Incapable of being troweled satisfactorily, the adhesive “balls up” under the trowel, and is usually due to a dusty or dirty substrate. 
May also occur when the adhesive has been frozen.
Undesired migration of materials in an adhesive to the surface of the floor between seams. 
May be caused by moisture in the subfloor, not enough open time, too much adhesive,
solvent removers in the subfloor.
Bond The adherence of one material to another.
Charcoal Lighter Fluid Fluid used to light charcoal grills.  A mild solvent used to clean adhesive residues.
Contact Adhesive
An adhesive applied to both surfaces to be bonded and is allowed to dry to the touch. 
It bonds to itself instantaneously on contact.  Since this type of adhesive does not remain tacky, it must not be allowed to dry.
Coverage  To overlay or spread with something usually measured in square feet or square yards.

Refers to asphalt adhesives which have been liquefied with solvents. 
When the lighter factions are boiled away from petroleum oil the thick residue left is asphalt. 
To make it fluid again, solvent is added or the asphalt is ‘cut back’.
To change the physical state of an adhesive or an adherent by the loss of solvent or water evaporation, absorption, or both.
Dry to the Touch  Dry to the touch is when you place your fingertips lightly on the adhesive ridges, no adhesive transfers to them.

Products formulated to be environmentally compatible, they meet the following: 
1) Low or no VOC content (calculated at 70 degrees C, SCAQMD) which means less than 150 g/l. 
2) Low odor – does not contain ammonia. 
3) Low or no organic solvents. 
4) No reportable hazardous substances per current regulations. 
5) Nonflammable.  These products continue to provide the working and handling
characteristics required of a floor covering adhesive while providing the environmentally compatible characteristics on today’s market.
Epoxy Adhesive  A very strong two-part thermoset adhesive which is mixed on the job.  Depending on the use, epoxies can have short or long working times.
Extremely Flammable Having a flash point of less than 2 degrees F.
FlammableHaving a flash point of 20-80 degrees F.
Flash Point  Temperature at which an inflammable liquid produces a vapor which, when mixed with air, becomes an explosive mixture.
Freeze-thaw Stable
Freeze-thaw stable adhesives are not as prone to the cold weather damage as other adhesives but they must still be treated with care. 
Most freeze-thaw stable adhesives can be thawed and used if the temperature has not dropped below 10 degrees F.
Full Spread InstallationSpreading the adhesive over the entire substrate before placing the flooring.
The property that enables an adhesive film to hold in place an adherent which is trying to pull away.  This is usually applied to a partially set film.

Long strings of adhesive developed between the flooring and the substrate as a result of the water evaporating or migrating from the adhesive. 
This is normally seen in rubber-based adhesives and is a desirable characteristic. 
It is important to remember that not all adhesives have legs and legs are not a necessary characteristic for good adhesion to occur.
Relating to flooring adhesive and sometimes even to latex primers.  It is normally associated with water-based products and is a catchall term.
Open Time
Amount of time recommended for the adhesive to set before it is covered with the flooring. 
Open time is affected by temperature, humidity, and porosity of the substrate.
Pot Life
The amount of time a product, which must be mixed, remains workable in the original mixing container. 
Generally applicable to two-part epoxy adhesives and powder underlayments.
Shelf Life
The period of time which a manufacturer guarantees the unopened adhesive will be usable. 
The date of manufacture is normally stamped somewhere on the adhesive container.
South Coast Air Quality Management DistrictSCAQMD is based in Orange County California.  They have established the requirements for figures of grams per liter for VOC’s. 
There is a formula they use to calculate the figure.  Their website address is
Spread RateThe amount of coverage which can be expected from a given amount of adhesive when spread using the recommended trowel.
Strings  Long “strings” in the adhesive, normally while still in the container, are usually a result of instability.  These are an undesirable characteristic.
Trowel  A hand tool with notches used for spreading adhesives onto the substrate. 
Trowels are recommended with notches that leave adhesive ridges of a size which will ensure complete contact with the flooring being installed.
Working Time
When installing flooring, this is the amount of time allowable from the laying in of the flooring until all cutting and fitting must be completed. 
Temperature, humidity and porosity of the subfloor affect working time.
Updated on October 26, 2022