Trim Tile
All tile is either field tile or trim tile. Field tile is the main set of an installation. If it is glazed, it is glazed on the top surface only. Trim tile is glazed on one or more edges and is specially shaped to border and complete the main field of most installations. No trim tile is used for floors tiled right to the walls, unless there are baseboard tiles around the perimeter. Trim tile comes in a variety of shapes, sizes and colors to match many, though not all, lines of field tile. In general, this trim tile falls into two broad categories: surface trim and radius trim.
Surface trim
Surface trim which is sometimes also called bullnose, is basically flat tile with one edge rounded over. This tile is used at the margins of an installation whose setting bed is flush with the surrounding surface. You will sometimes see surface tile used at the front edge of some countertops, on windowsills and at the top row of backsplashes or tile wainscoting. Sometimes a second rounded edge is added to surface bullnose to make a trim piece called a down angle, which serves to finish off an outside corner. If only a single corner on the tile has been rounded or curved, the trim piece is called an up angle and is used to finish off an inside corner. If a line of bullnose trim does not include a down angle or a sink corner, regular surface bullnose can be mitered to form this configuration.
Radius trim
Radius trim, also called radius bullnose, is curved trim tile that can be used to complete the same installations as those mentioned for surface bullnose, except that it is designed for installations whose setting bed sits above the surrounding surface (usually a traditional mortar setting bed, or backer board mounted o existing drywall). Like surface bullnose, radius trim is usually available in a variety of shapes, including down and up angles well as quarter-round pieces called beaks, which finish off quarter-round trim. In addition to surface and radius bullnose, complementary pieces like speed cap and V-cap for countertops and cove trim are also often available, enabling a setter to finish off almost any imaginable installation.
If a line of tile lacks a coordinated area of trim, some manufacturers produce pieces of field tile with one or two glazed edges, which can serve as finishing trim.
If no trim at all is available for the tile you select, look for another line of tile. Sometimes a very similar trim can be found, or a contrasting color may look good. If the trim pieces are larger than the tile you’re working with, they can be cut to size.
In the case of unglazed, soft-bodied tiles like Mexican pavers, for which there is usually no trim tile, a substitute can be made by rounding the edge of a flat tile with a masonry rubbing stone or a small hand grinder. Rounding two of the tile’s edges produces a down angle, while rounding one of its corners creates an up angle. If the trim is needed for outside angles, for example on a staircase, it may speed up the process and make for a neater finished appearance if the tiles are rounded after being set. The sealer used for the surface of this tile will, of course, need to be reapplied to the newly rounded edges.
Finally, an alternative to trim tile that’s gaining in popularity for finishing the edges of countertops is wood trim. Although this trim may be much less expensive than ceramic trim, combining these two materials in a wet installation raises problems. The wood expands when it gets wet, while the tile does not. For this reason, the joint between the tile and trim must be caulked to prevent the inevitable cracking that would befall a grouted joint there.
