How to Install the Backer Board for Bath Tile
- 1). Prepare the bath area for the backer board installation. Attach continuous layers of 15-lb. building paper over the wall studs, beginning at the bottom of the walls. Secure the building paper to the wall studs using a staple gun, making certain the corners are tight to the framing. Also, lap the horizontal rows a minimum of three inches over the row beneath for moisture drainage protection.
- 2). Measure the horizontal wall dimensions for the first panel of backer board. The backer board should fit over the full wall length or be cut to end on a wall stud for proper backing.
- 3). Mark the dimensions determined in Step two, if less than a full-length panel, on both edges of the backer board panel, then connect the marks using a chalk line. Cut the backer board panel on the chalked line using a utility knife or circular saw with a masonry blade.
- 4). Place the first piece of backer board horizontally across the wall, held approximately 14 inches above the tub platform or shower base. Verify that the backer board panel is level, then secure in place with backer board screws through the panel into the wall framing. The screws should be spaced approximately eight inches apart and driven flush with the panel surface.
- 5). Repeat Steps two through four to install backer board panels over the area to be tiled. Cover all the joints between panels, spanning them with webbed fiberglass joint tape to complete the backer board preparation for tiling.
Source...