The title of this article is slightly misleading since most tile installations – even straight installations composed of a single color – are the result of a pattern. For simple, single-color tile installations, the installation pattern is actually an ANSI A108 standard (A108.02, 4.0, 4.3, Workmanship, cutting, and fitting). The first two parts of this standard, 4.3.1 and 4.3.2 cover centering and balancing, and the no-tiles-less-than-half-size rule, and are the foundation of most tile installation layout work. Regardless of the pattern, and in spite of the fact that most tiles are not perfectly sized, the tile industry recognizes that a mathematically precise layout is required for the finished tilework to look craftsman-installed and beautiful.
Of course, one of the simplest of all patterns is a rather chaotic method of installation called rubble-style, in which the tiles are shattered and the resulting irregular-shaped pieces are jammed against one another without regard to place, position, or joint uniformity. There is no doubt that the very first floor tile installation, made from thin stones, was laid down rubble-style, without benefit of a layout; so if this is your style, grab your hammer and start smashing. If you intend to deal with squares and rectangles, though, there are almost an infinite number of choices. Let’s start with a pattern of one.
By a pattern of one, I mean an installation layed out with the joints parallel to the surrounding walls and finished with a single-color square tile. This is the most basic pattern for all types of tile installations, but as the first three drawings reveal, there is more than just one or two approaches to the basic pattern. Illustration 1 shows the most economical use of tile, but its slender cuts draw attention to themselves and problems with the wall, and they detract from what might otherwise be an attractive floor. The less-than-half sized cuts do not meet the ANSI standard. This is an example of a pattern that results in an unattractive installation. Aesthetically, the small tiles may be acceptable, but sliver tiles are unable to absorb and distribute loads like full-size tiles, and in a commercial application, they are likely to fail. This sample installation requires 42 whole, and 14 cut tiles. Illustration 2 shows the same relative size with the layout shifted to produce a relatively balanced perimeter whose cut tiles all exceed half-size. At this size, all the cuts meet the ANSI standard, and are better suited for commercial applications. As you might expect, this pattern uses more tiles and more labor: 46 whole, and 28 cut tiles are required.
Adding a second color is probably the next, most basic way to create a pattern. One of the world’s most notable and enduring patterns is the checkerboard. Use a pencil or pen to checkerboard the whole tiles shown in Illustration 2. While you are at it, to illustrate another basic pattern concept, color in the cut tiles around the perimeter of the floor, and turn them into a border.
A fourth basic pattern concept is to orient the tile joints diagonally. Illustration 3 uses the same space and relative tile size as the previous examples to plot a diagonal layout pattern. As with the off-balance layout in Illustration 1, the tiny triangles that result on two sides of the space look off-balance and draw the eye to the small cuts. I prefer diagonal floor installations, but I won’t install one without a border. Illustration 4 shows the same floor space and tiles with a diagonal/border layout that has been used since the time of Pythagoras (around 500 B.C.), whose 3-4-5 triangle is used around the world by installers to build square and true. At 42 tiles, this layout requires no more than a square layout, but it needs 33 cuts for the diagonal insert and the square border. All the half and quarter diagonals, because of their sharp points – and a cut edge that is exposed - require careful cutting and finishing. Also, the sharp points need to be fully supported with thinset mortar.
With this method, I use only whole tiles and half- or quarter-diagonal cuts to make the diagonal insert, and when practical and possible, maintain a border width no less than half the size of the field tiles. The border is meant to be a frame for the main portion of a floor, and it can be extended with one or more rows of tiles to cover irregular areas (Photo 1) If the layout of the diagonal insert flows well into an adjoining room, I continue the insert and the border, but if the layout does not work, I contain each room’s diagonal insert with a separate border (Photo 2). Diagonal floors can be done checkerboard style but as Illustration 5 shows, the layout of the diagonal insert must be based on quarter-diagonal corners: when a diagonal checkerboard is specified, I sometimes need to make the border wider to make this happen.
With the layout skills to complete a square or diagonal floor that meets the tile industry’s ANSI A108 installation standards, you should be able to tackle any of the countless patterns that are available, like basket weave, herringbone, square-and-spot (one of my favorites), and others. To learn more about the decorative nature of ceramic tile, I suggest you look at the impressive list of books and reprints available through the Tile Heritage Foundation (www.tileheritage.org). TCA, ANSI A108 and ANSI A137 Handbooks are available from www.tileusa.com.
Many tile manufacturers offer on-line design and estimating tools that can be especially helpful when working up a materials list. A good example can be found on DalTile’s website (go to www.daltile.com, and follow the design links to TILE PATTERNS). Why go plain when it is so easy to get fancy?