Water_resistant backer board, not drywall, should be used under tile that is likely to get wet (shower walls and bathroom floors, for example). Whether it's backer board, plywood, or concrete, the substrate needs to be sound, clean, and dimensionally stable. Surfaces need to be level or plumb and true to plane, as the pros say__that means no bumps. Wallpaper, loose plaster, flaking paint, peeling tiles or unsecured sheet flooring must be removed from the walls or floors that are to be tiled.
Once you've identified the center and baseline from which you will work, snap a pair of perpendicular chalk lines. These will divide the room into roughly equal quadrants. You'll want to work outward from the center point in each of the four sections.
by Helen K. Patel on Jul 31, 2018 Ceramic Tile