“You are not saying we can glue 3⁄4” solid wood over concrete, are you?”Well the answer is yes and no. When we say 3⁄4” wood flooring we are not speaking about your average wood that is bowed and bent. Such flooring, like unfinished 2 1⁄4” strip that requires mechanical fastener to hold it down and pull it together tight can not be glued down. It requires nails or staples, period.
Fortunately, however there are many pre-finished and unfinished solid products available which are relatively straight, flat and rack together easily. These products, regardless of species, thickness or width can be glued down successfully over concrete or gypsum-based sub floors. The only limitation is the slabs must be above or on grade. Installations of solid wood are never recommended below grade.
The other concern has always been that water in a concrete slab will be absorbed by wood flooring. With the use of Products lik Bostik MVP4 urethane membrane we can eliminate that problem. However, as with nail down floors, we still need to be concerned with housekeeping and humidity in the building. There are more ways for a floor to become saturated with water than the subfloor.
There are literally millions of square feet of solid wood flooring glued down throughout North America in residential and commercial applications.
Be warned, solid wood flooring is not as forgiving as, dimensionally stable cross grain laminated, engineered products. If you skimp on acclimation, surface prep or adhesive, call backs are likely. However if you take the time to understand the installation of solids, you will be able to offer a more diverse range of wood flooring in glue-down markets.
All of Bostik’s urethane adhesives are recommended for solid glue down jobs. But don’t try to bond solid wood to old adhesive residues, cutback or concrete sealers. These products were never designed to withstand the lateral expansion and contraction of solid wood.