I expect that most of you are well aware of the general subfloor requirements and limitations for all resilient floor coverings. This includes the variations with flatness, expansion gaps, moisture limits—and some will even talk about pH—but to the relief of many at the ASTM F06 committee, I am not going down that road today.
A little while back, I was evaluating a claim for one of our SPC products, in this particular product the locking mechanism used is an “angle-drop-lock”. For those unfamiliar with this, basically the long side joint is first engaged at an angle, then you slide the floor covering to line up the end joint, lower it down, and tap along the high side with a 1 lb. soft faced dead blow hammer or rubber mallet to lock the joint together.
Skilled floor covering installers will tell you that with any floating floor installation, making sure the first row is straight is crucial to having an easy day, regardless of who makes it or what locking mechanism is used. When you take the time to start off straight, the plank or tile joints line up and connect nicely. For this reason, my installation instructions state, “Keeping the installation straight is critical, so check the first row using a chalk line or similar, if needed, adjust and firm up the row by adding more wedge spacers.” When writing that line, I had solely the do-it-yourself audience in mind. I never thought of this as something I would need to tell installers.
This particular claim was clearly installed in a straight line that resembled a banana. The result was broken end joints and an unhappy end user, hence the claim. The installer, who shall remain nameless, stated that his installation was indeed straight and that the V-shaped gaps at the ends were merely a result of the planks being manufactured out of square. Now, obviously, the squareness can be tested to prove the product was manufactured square, or at least to within its required ASTM specification. It is also easy to use a string or laser line to prove that an installation is not straight. Or is it? That’s when it dawned on me that we have no acceptable straightness tolerance for installations.
We have a manufacturing tolerance of straightness, and if we use that, it is then impossible to install the floor covering perfectly straight. The logical result is that we must also have an acceptable tolerance for the installation. One of the first things I learned when I entered this industry was the “CYA” rule. I checked several ASTM documents, asked an independent inspector, and even some of my technical friends at other manufacturers—nobody had or knew of any such tolerance. Indeed, I quote, “but if it’s not straight, it won’t go together properly”, which was kind of my point. But if a tolerance is not published, and “straight” is impossible, then you have no limit, and therefore claims cannot be denied based on a lack of straightness. Think about this: it applies to just about all of the floor covering products available. Needless to say, I have now added an acceptable straightness tolerance to our installation instructions.