How to Lay HardiBacker Board
- 1). Measure the length and width of the room and multiply the two for the total square footage. Lay out all of the pieces of Hardibacker on the floor. Check that all seams in the floor are covered. Leave a 1/8-inch gap between the boards themselves.
- 2). Mark along any boards where cuts will be made. Line up a T-square and draw a straight line with a pencil at the cut marks. Score along the mark on the board with a utility knife. Move back and forth and score the board until the blade is almost through the other side. Snap the piece into by hand and repeat the process for any other pieces.
- 3). Apply a thin, even layer of thinset mortar with a trowel in the bottom corner of the room. Spread it out evenly over the entire surface and press the board into place. Run your hands over the entire board to make sure it thoroughly adheres to the sheathing underneath.
- 4). Screw the Hardibacker into place with 1 1/4-inch Hardibacker screws. Place a screw every 8 inches apart and 2 inches from the edge of the board around the outside. Offset the inner screws from the outer screws. Drill the screws until they are flush with the surface of the Hardibacker.
- 5). Butt the second sheet up to the first leaving a 1/8-inch gap. Install the second sheet and all of the remaining sheets just as the first was installed. Cover the seams between the sheets with thinset mortar. Spread it out with a trowel. Tape over the mortar with Hardibacker tape. Press the tape over the seams.