From the Floor Up, a Blog for the Flooring Professional From the Floor Up, a Blog for the Flooring Professional

The Truth About Gluing Solid Wood Flooring to Concrete

Monday, June 22, 2009
We get questions all the time about our claims that we can glue down solid wood over concrete.
“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.

Bostik TruColor Pre-Mixed Grout

Monday, June 8, 2009

TruColor Pre-Mixed Grout is be available in 20 colors unique to the Hydroment® and Durabond® brand product lines of tile and stone setting materials. Additionally, when used in conjunction with a Bostik system of products, TruColor Pre-Mixed Grout will be warranted up to the length of the system used!

TruColor Pre-Mixed Grout is a patented, water-based, urethane grout offering the ultimate in color accuracy, stain protection and crack resistance for residential and commercial tile installations. This breakthrough formulation installs up to 50% faster than traditional grouts, and never needs to be sealed! Its perfect balance of flexibility and toughness enables it to exhibit unmatched performance and crack resistance. TruColor Pre-Mixed Grout exceeds the grout-relevant portion of the ANSI 118.3 epoxy standard (modified ANSI 118.3-UG).

TruColor Pre-Mixed Grout Tips on Mixing and Cleaning

Urethane grout is an easily installed product, but it is different to use than conventional grouts. We will review the mixing and cleaning protocols that we recommend to our customers.


There are two ways to mix urethane grout. We always recommend and prefer that the customer hand mix the product with a margin trowel. If the customer prefers to use anelectric mixer be sure to remind them to only mix for ONLY 30 seconds on low speed (it is really easy and fast to bring this product into suspension with an electric mixer).
After mixing with an electric mixer the product should stand 10 minutes before use. The use of an electric mixer will add air to the grout mix causing potential slumping in vertical applications and sinking in some floor applications.

Note: The customer should continue to stir the grout with a margin trowel during grout application.


There is no easier grout to clean in the industry as long as you clean correctly. Spread the grout using a green epoxy rubber float. Only spread an area that you can reach and then immediately clean with clean water (this is a clean as you go product). As you are wiping the surface make sure the sponge is wrung nearly dry. Since the float removes 95% of the grout from the surface you need little water to clean the surface. Additionally, the less water you use the faster the product will cure. Remember urethane grout is an air dried product and cure is dependent on temperature and humidity.