It goes without saying that today’s tiles come in more sizes, shapes, patterns and colors than ever before. Along with this availability comes virtually endless creative possibilities. Today we will focus on one of these options—the pattern.
When using an offset pattern, it is best to follow the American National Standards Institute (ANSI) guidelines. ANSI A108.02 section 22.214.171.124 states, “For running bond/brick joint and any offset pattern (i.e. non-continuous grout joints) utilizing tiles (square and/or rectangular) where the side being offset is greater than 15 in. (nominal dimension), the offset pattern will be a maximum of 33% unless otherwise specified by the tile manufacturer. If an offset greater than 33% is specified, specifier and owner must approve mock-up and lippage.”
The ANSI guidelines provide even more guidance to the installer. ANSI A108.02 section 4.3.1 states, “Center and balance areas of tile, if possible” and ANSI A108.02 section 4.3.2 tells us, “An excessive amount of cuts shall not be made. Usually, no cuts smaller than half size should be made. Make all cuts on the outer edges of the field.”
However, when offsetting the pattern by 33%, it can be challenging to provide equal cuts on each side of the wall being laid out and not have less than a half tile in the next course. In this case, the one-half-tile-or-larger rule may need to be set aside. When this occurs, always obtain the owner’s approval on the pattern layout to be certain it meets their expectations.
The problem gets worse if two intersecting walls meet at the inside corner with each wall ending up with small cuts, as seen in the attached photo. In tile industry slang terms, we have what is known as a “sliver cut” or “rat tail.” These cuts look really bad to the unsuspecting consumer who views this installer error. The regrettable result is that when this same consumer is looking for an appropriate product for their home or business, they will remember the unsightly installation and say to themselves, “If that’s the way tile looks, I don’t want it in my house.”
There are a couple of other issues involved in this installation. None of the grout joints are the same size; the corner is not plumb, which causes the sliver cut to get smaller going from top to bottom; and the inside corner is grouted rather than being a soft joint with 100% silicone sealant. Had the installer shifted the layout just 3/4 in. on each wall, the rat tails would disappear.