Adhesives

The first thing a manufacturer's rep will do when inspecting an issue relating to a hardwood floor is to remove a few boards in order to inspect the adhesive used. If it is determined that the recommended adhesive was not used, then your warranty will be void and you will not be able to submit a claim, regardless of whether the issue is adhesion related.

VOCs (volatile organic compounds): VOCs contain hazardous chemicals that are found in finishes and other common household materials. When shopping for an adhesive, it is important to ensure that the adhesive does not contain a high level of solvents, and that it is VOC complaint.

Manufacturers recommend different kinds of adhesives based on the construction of the hardwood floor and the type of existing sub floor. The following are adhesives that can be used for installing hardwood floors:

Urethane:

A moisture cured urethane adhesive that contains no water. It cures by absorbing available moisture which causes a chemical reaction. Once cured, these adhesives are not affected by water. Urethane adhesives offer the strongest bond and can be used when installing solid, parquet and engineered wood floors. Urethane adhesives can be used over the following substrates: concrete, suspended wood and wood underlayments, existing resilient flooring, primed and poured in place gypsum sub floors, ceramic, cork flooring and acoustic cork. Urethane adhesives can be installed over radiant heated floors provided the surface temperature does not exceed 80-85 deg F. Most Urethane adhesives are VOC compliant and are low in odor. They are water proof and dry slowly, allowing for product repositioning. They remain Electrometric, allowing for movement due to expansion and contraction of the hardwood floor. Urethane adhesives can be used in above, on and below grade installations. When using a urethane based adhesive, it is important to clean any residue promptly, as once dried, it is very difficult to remove and will require the use of a urethane adhesive remover. The only down side to urethane adhesives, is that they are more expensive than other adhesives.

Water Based Adhesives.

Water based adhesives do not offer the same bonding strength as urethane adhesives and are limited in application. Water based adhesives are generally free of solvents and VOC's. They are easier to work with and easier to clean, however they dry quicker and do not display the same elasticity properties as urethane, thus not allowing for repositioning of boards. Their range of application concerning certain types of wood floors construction and sub floor type is limited. Always refer to manufacturers recommended guidelines for suitable applications of water based adhesives

There are many more types of adhesives available to the consumer, such as: Cross linked Resin Adhesives, Polymeric Resin Based Adhesives, Tri-lingual adhesives etc, most of which can be classified as water based, solvent based or urethane. If you are not a scientist, then most of it means nothing, except for the fact that they are approved for use with hardwood floors. Each manufacturer carries a selection of urethane and water based adhesives which they recommend for use with their floors.