Ceramic Tile Preps
Before getting down to laying out the tile, remove the doors from their hinges and molding from the walls. As tiling will significantly raise the level of the floor, it is possible that the doors will have to have a bit cut off from their bottom before they can be replaced. If you are working on a bathroom floor, remove the toilet and any other fixtures that are removeable and that will have to sit on top of the tile.
For walls, floors, and countertops, be sure that the surface you will be tiling is as regular as you can make it. Any time that a tile is laid on an irregular surface, chances are it will be broken. This means no nails protruding from the floor, no significant cracks, holes or dips. On walls, these irregularities can be smoothed over with the application of plaster, and possibly some sanding. The floor can can be adjusted depending on the surface. Cement floors can be evened out with cement patching compound. Wood is usually quite flat on its own, makes sure the underlayment is fit together closely to avoid gaps.
It is best not to try to tile over old tile, ceramic or otherwise. Be careful in removing old non-ceramic tiles as they may have been made of asbestos. In this case, be sure to wear a mask to avoid getting dust or fibers in your lungs. In the case of tiles made with asbestos, many home-owners prefer to have the job done by a professional.
Be sure the surface is dry and clean before work begins. Dirt can not only gum up a job, but debris can cause the adhesive not to stick properly. If you are installing tile in a shower or similar location, be sure the proper water resistant drywall is used, or better yet, use a cement board (sometimes called wonder-board).
You may generate a degree of dust, so it would probably be wise to cover any air ducts. There may even be an occasional flying chip of tile due to cutting or nipping, so besides taking the usual safety precautions you may wish to remove anything that might be broken. Also, tiling requires that there is a fairly large surface that is not to be walked on or touched, be sure that the area in which you are working is secure from human and animal traffic.
When your tile and tools are laid out, you are ready to begin.