Porcelain, ceramic and stone tile imparts a long lasting and easily maintained surface for bathtub surrounds and shower walls. The layout of the tile, according to industry standards, is the same for any other tiled installation.
Simply put, layouts should be centered and balanced if possible,excessive cuts should be avoided, attempt to have no cuts under 1/2 tile, and fit trim closely and uniformly. Also, where dimensions are stated in feet and inches, maintain tile work in full tile courses.
Refer to the above diagram. This is a simplified illustration of the layout process for a three walled tub enclosure or three walled shower. Note the locations of the full tile. Generally, there should be full tile in the first course at the front edge of the installation. Any cuts should be made at the back wall interface.
The installer has the choice of centering the back wall tile especially if full tile will fill the space. Often it is visually best to start at either the left or right side of the back wall with a full tile and make a cut at the opposite end if the tile at the cut side is 1/2 tile or greater.
For enclosures that have a design element, centering the back wall tile is usually the only option so that the deign element flows from one side all the way around the enclosure.
For tub and shower enclosures, starting at the back wall and establish a centered vertical line using a trusted spirit level. Why trusted? If your level is not accurate, your line will not be plumb. This will throw the entire layout out of whack.
To check a spirit level, place the level on a horizontal surface and shim to exact level (if necessary). Make the precise location of the level and rotate the level 180 degrees (turn the level around). If the bubble is in the exact same spot, the level is accurate. The same technique can be used for plumb.
This initial line should extend from the base of the installation to the top or where the tile will end. Next is the horizontal line.
If the tub is properly installed securely and level, tile can be stacked and adjusted using the tub as a ledger to keep the tile from sliding down the wall. Self spacing tile, shims, or tile spacers support the upper courses of tile. Small adjustments to level the tile can be made by shims or even cardboard strips made from tile boxes. Removing these shimming devices and spacers prior to grouting is mandatory.
Tile Doctor Tip: Remember, current industry standards indicate the use of a sealant at the tile-tub interface, not hard grout. Hard grout in this area is likely to crack and dislodge.
If the tub or lower element would prevent its use as a ledger, a ledger board temporarily fastened to the wall may be necessary. A ledger board is also used in the case of a shower where floor mortar will be placed after the wall tile is installed.
For a detailed look at the placement and use of a ledger look in "Showers"