Installation of Custom Tile Patterns
Basic Layout Skills
Often, the simplest of designs is ruined because of a poor layout. The tile industry has a number of layout standards that can be found in the "American National Standard Specifications For The Installation Of Ceramic Tile (ANSI A108-1999," available from the Tile Council of America, 864-646-8453, www.tileusa.com). Under A-3.3 Workmanship, cutting, and fitting (on page 33 of the ANSI booklet), there are only six standards that apply to all tile installations, and most of the concepts, at least, should be familiar to floor covering veterans: center and balance cuts (wherever possible); no cuts less than half size allowed (except under certain conditions); keep all visible cut edges smooth; observe the fit when working around penetrations (pipes, valves, vents, etc); no splitting of tiles (holes should be drilled through tiles to accept plumbing or other penetrations; and, for wall installations, maintain heights of tilework in full-tile increments (except where a vertical space is to be completely filled, and in this case, any cuts should be located in the first or lower course of tiles).
I work under the assumption that most baseboards are not straight enough to serve as a baseline for a layout, so I use the centerline method and create my own reference lines with the help of a laser square. I try to do this work during low-light hours using a three-step process: measure the area to be tiled, measure the tiles, and apply layout lines. The laser, literally, is light years ahead of the traditional chalk line during the site-measuring phase, and can be especially helpful for the A&D tile installer.
Another laser, designed for walls and projecting vibrant cross-hairs, is an essential layout tool when wall and floor or ceiling tiles meet.
Inlays and Borders
One of the easiest ways to impart individuality to a tile installation is with a border or inlay. Borders and inlays can contrast the field tiles, and they can also complement them, as what happens when the field tiles themselves are used to make up the border or inlay tiles. Photo 1 shows a traditional design made from a mixture of cut field tiles and left-over stone tiles. To help create this pattern and make it more flexible, modular corner and cross pieces were pre-cut and installed first, with the narrow strips cut and centered to suit the required length.
Whenever possible, borders should wrap around fields of whole tile. In fact, a border can be an effective design tool when dealing with an area that is difficult to layout. Photo 2 illustrates how a border is used to preserve the symmetry of a diagonal floor. Notice that only whole tiles plus either half or quarter diagonals are used to make the inlay; the border tiles frame the inlays, and help hide the usual fluctuations around the perimeter of the floor, and the matching baseboard tiles help to make the irregular width of the border invisible.
Because of so many variables when working with any design, I try not to cast any measurements in stone. Yes, it is possible to work it out on paper, and on some installations, a large-scale drawing may be required or desired when working out a design and dimensions, but invariably, the dimensions will need some adjusting in the field.
At the installation stage and on multi-room floors, I prefer to install the field tiles first, and the border and perimeter tiles second as a separate step. The same for most inlays made from consistently-sized tiles. For hand-molded or irregularly shaped tiles and some mosaics, though, there may not be any straight lines that can be used as a reference. For these tiles, special installation methods are required.
Art & Decorative Mosaics
Some mosaic tiles are so consistently sized that they can be mounted on modular sheets. There are even manufacturers that will compose a design on sheet-mounted, 1- or 2-inch mosaic porcelain tiles that are delivered with a tile-by-number instruction sheet.
Because the mosaic sheets used in the award-winning installation (shown at its beginning in Photo 4) are all dissimilar, the floor was completed without any layout lines. Typically, because this type of mosaic sheet has no regular reference points, I begin the installation by spreading out all the sheets, making sure the joints between individual sheets are properly spaced.
On this floor, great care was taken to ensure that the perimeter joints were even and consistent; initially the sheets were used to accurately trace the perimeter of the floor so that the wood plank floor could be cut to leave a 1/8-inch joint around perimeter of the leaf-shaped tiles.
After the edges of the wood planks were trimmed with an 1/8-inch router bit and sealed with finish, I installed a crack isolation membrane over the plywood underlayment, repositioned the mosaic sheets, carefully removed three or four sheets at a time to make room for a 1/4-by-3/8-by-1/4-inch square notch trowel (see Photo 5), and kept a close eye on the sheet alignment as the job proceeded. To keep cracks from appearing between the wood planks and the tiles, the 1/8-inch joint between the two materials is filled with a resilient, color- and texture-matched caulk instead of grout.