By Bob Goldstein
I have had a spate of calls recently about wood floor issues with brand-new floors not living up to what they are advertised to provide. Digging deeper with both homeowners and contractors, it turns out that these problems aren’t actually with real wood floors, but are occurring with “wood like” floors, either laminate or LVT, which tout being 100 percent waterproof.
Wood-like or wood-look products install much like real engineered wood floors, so the extra work offered to the professional wood floor installer is a positive thing if they educate themselves on the differences between the flooring and make sure they read all instructions. That last part is easier said than done. I visited several big box stores where the waterproof floors were being promoted. Not one could offer me a printout of the installation instructions or had any real-world knowledge of how to install them. I was able to get what I needed by calling the manufacturer’s tech support or chatting with an online person.
Here is one of the most egregious examples of throwing both the homeowner and the installer under the bus: 1,800 square feet of flooring installed in a home on a golf course in south Florida. The home is concrete slab on grade. The floor is a click profile floating product. Because both parties were assured that this flooring was 100 percent waterproof, no moisture testing was done on the concrete and no vapor barrier was used. (Keep in mind, the backing on this product is a layer of cork.)
Within two months, there was standing water in the kitchen, the flooring was delaminating, buckling, and the whole house smelled of mold. The original flooring in the home was carpet. I spoke with a tech support person about the issues with the floor and he told me to read the installation instructions and that moisture testing is required and a vapor barrier should be used if the moisture is higher than what they recommend. I was able to track down a PDF file of the installation instructions and found some very interesting information. They do say to check for moisture using the CM method (ASTM D4263) better known as the plastic sheet test. It further states that a reading of 2.5 percent is acceptable. This confuses me as this type of test doesn’t give a quantitative number; it’s either wet or dry, so what tool was, or is, used to get the 2.5 percent?
We should all be familiar with ASTM F1869 Calcium Chloride testing and ASTM F2170 in-situ probe tests. Both provide go/no go numbers; CC 3 pounds or less, in-situ probe, 75 percent RH or less for wood and related floors. So, if you get a number above the manufacturer’s recommendation, there is usually a remedy such as using 6 or 8 mil plastic sheeting under the floating system. Nowhere in the instructions is moisture mitigation mentioned.
The bottom line is that 100 percent waterproof floors are a myth. I looked at several brands with varied construction, all claiming to be waterproof, one made with MDF core (medium density fiberboard) with a sheet of closed cell foam glued to the back. How is this supposed to stop moisture from under the floor getting to the fiberboard? As mentioned earlier, some have a cork backing, which also is not waterproof. Others have a HDF (high density fiberboard) core that is coated, but they still recommend cleaning up spills right away.
I bring these issues up because a lot of wood floor folks took it on the chin with overly ambitious claims from some bamboo manufacturers over the years. We learned the hard way that solid bamboo must be treated like solid wood and acclimated to its in-use environment out of the packaging. Strand-woven bamboo also needs to be acclimated like real solid wood, keeping in mind that acclimation for these products takes longer than real wood due to the resins and glues that hold them together, and the fact that they are finished on all six sides. Because the installation instructions for so many of these floors (even now) can be ambiguous, the finger is always pointed to the person who did the work.
My advice is simple: CYA – cover your assets! Read all instructions and then opt to be very conservative, use your acquired knowledge and experience and reach out to the NWFA for suggestions and options when any part of the installation process feels wrong or instructions are vague.
One last point. An old saying that we have always used during NWFA training: “Sometimes that job you chose not to do turns out to be the best job you never did.”
Bob Goldstein is in Technical Services, Training & Sales at Vermont Natural Coatings based in Hardwick, Vermont. He can be reached at email@example.com.