Hardwood Floors February/March 2024

AT THE SITE Mastering Moisture in Your Subfloors to learn. Your local manufacturer’s rep can provide training to get the best results. These are some of the more-common types of moisture mitigation systems. It is important to have your moisture testing results so you can compare them to the solution and be sure the product will meet or exceed your test results. • Acrylic and latex-type products often are less expensive and may offer some protection, but only up to a certain level. • Urethane solutions can offer even higher protection and sometimes apply in one to two coats. • Epoxy two-component systems offer the best protection up to 100 percent relative humidity in most cases. Certain precautions must be taken during installation for proper disposal and safety. Epoxy application is something that can be learned and is an additional skill set that can help you stand out amongst your competition. • Plastic or poly sheeting still is utilized in properly prepared crawlspaces where hardwood will be installed over plywood or OSB substrates. This is a simple and cost-effective method, but ensure any flashing, overlapping, or taping of the seams is done thoroughly with no places for the moisture to escape. Also, pay attention if any cross ventilation is present as recommended by NWFA guidelines or manufacturer recommendations. When it comes to traditional plywood subfloors, there is a newer method available referred to as liquid-applied vapor retarder. Traditionally, hardwood floors have had either tar paper or a similar semi-permeable vapor retarder installed onto the plywood subfloor using staples or fasteners. Aside from the additional time installing the paper, if a glue assist was required or recommended by the manufacturer, in the past, you had only two options. The first option is to remove this vapor retarder completely because a bead of adhesive on top of a slip sheet of paper does not do any good. I admit I was never fond of this strategy because I have now eliminated the protection I had from moisture in the substrate. The other option is to cut slits into the vapor retarder to allow the adhesive

from your glue assist to contact the plywood substrate underneath. The problem here is obvious: we now have slits or holes in our vapor retarder anywhere we have applied the adhesive. These updated methods for semi-permeable vapor retarders allow for a single coat applied to the plywood or OSB, often dry within an hour, and then allow for the use of penetrating hardwood fasteners, including staples or cleats with the addition of glue assist. While these products cost more than a paper roll, a great deal of time can be saved by eliminating the installation of the paper itself and having a more solid method for your glue assist hardwood installations. Solving the common problems of substrate moisture does not have to be a mystery when you have access to a variety of solutions. Jeremy Waldorf is regional business manager for Schönox HPS North America, LLC in Michigan and Toledo, Ohio. He can be reached at jwaldorf@hpsubfloors.com.

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