In an ever changing world new technology exists all around us. Adhesives for floor covering are no different in that respect. The most common misconception about adhesives is “that’ll do.” Adhesives are not only designed specifically for certain applications but are also product specific. You wouldn’t take a knife to a gunfight would you? It just doesn’t make sense. Nor would you use a water-based adhesive with a thin solid hardwood floor. That doesn’t mean it can’t be glued down; it’s just probably not a good idea to glue down a 5/16” solid product with a water-based adhesive. It will look fine during the installation, but go back after about an hour and I am sure you will find a very nasty surprise. This is why adhesives should be product and application specific. You will find most adhesives do exceptional jobs and a job failure is not usually the fault of an adhesive. Now don’t get me wrong; there is the occasional bad potato that gets in the stew and doesn’t measure up to manufacturer’s specs but they are usually far and few between with the advancements in adhesive technologies.

Adhesives are generally designed for a specific circumstance and or product.

Allow me to elaborate a bit. As a general rule, water and wood don’t mix. However, that doesn't mean all of the time. I revert back to the statement at the beginning of this column. Technology is changing everything. With the advancements in production of engineered floors, water based adhesives are becoming more acceptable. But even water has its limitations. Think about it, if you were installing a very thin engineered floor, i.e. 1/4" or 5/16" would you want to use a water-based adhesive that had a large concentration of water in its chemical composition? Of course not; the moisture migration from the adhesive to the back of the wood flooring and the absorption would be much greater because of the thinner layers. However, if you were to use a water-based adhesive on a 9/16" or 1/2" product it would be much more difficult for the floor to cup due to the thicker layers. Water/latex/acrylic adhesives are generally a little less money and are environmentally friendlier. However, when used in the wrong installations become disastrous.

Key things to note:

Thickness of the wood to be installed

Dimensions of the trowel

Subfloor thickness and composition

Moisture test -- Calcium Chloride.

There are many alternatives to water based adhesives and I will explore and few of these and give some of the advantages and disadvantages to each.

Moisture Cured Urethanes: These are some of the most common adhesives on the market today. The advantages are that it has no water, has shear strength, and good tensile strength. As long as the subfloor isn’t wet, this is all you need. Disadvantages are: doesn’t spread very easily; as a moisture-cured product, Relative Humidity will play a major role on curing and open time; and it contains isocyanates and sensitization can occur after prolonged use. Isocyanates also damage the surface of pre-finished flooring if left on the surface too long. They are very difficult to clean up.

Solvent-Based Adhesives: These left the market about 10 years ago, but there are some newer technologies in this category too. Advantages: Performance is unmatched; Quick grab (green grab); it spreads easily; and cleans up easily off of boards and installers. The disadvantages are that it has an odor (solvent), and it’s flammable. Some will argue this is perhaps the best adhesive available.

MS Polymers and many other types of adhesives are on the cutting edge of technology  in the adhesive world. Advantages are: easily spreads; easily cleans up; and no VOCs, isocyanates or water. These adhesives are fantastic in composition and are environmentally friendly. They are almost safe enough to eat.

The only disadvantage to them is that they do not adhere well to closed-cell surfaces, such as marble or sheet vinyl.

As you look for adhesives, always consider the following and don’t concentrate on the cost of adhesive. After all, Shouldn’t you pass that on to the customer?

1. Species and Dimensions of wood.

2. Determine how susceptible to moisture that flooring is.

3. Check the sub floor and do your prep work.

4. If a moisture barrier is needed, pick a system and not just any moisture barrier with any adhesive.

5. USE THE MANUFACTURER’S RECCOMMENDED TROWEL. IT’S A MEASURING DEVICE TOO!

If you look at all of the above and think of how a  job may turn out, take away the guess work! Don’t skimp on adhesive. After all, it’s what differs a good job from a bad one and ultimately its what distinguishes you as a good installer from a bad one.