How to Install a Hardibacker Underlayment
Underlayment is the material that you put down above your subfloor to create a base for your top flooring. Plywood is a fine underlayment for a wood or vinyl floor, but if your flooring is going to be ceramic or other hard tile, you should go with cement board, because it’s more solid. Cement board comes in thin sheets and looks similar to drywall, but is harder and waterproof. Hardibacker is a top brand of cement board. Does this Spark an idea?
Things You'll Need
- 5/8-inch cement board
- Pencil
- Thinset mortar
- Notched mortar trowel
- Screw gun
- 1 1/2-inch galvanized screws
- Jigsaw
- Mesh adhesive drywall tape
- Drywall knife
Instructions
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1
Set a sheet of cement board in the corner of the floor. Use your pencil to trace on the floor around it.
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2
Pick up the board. Use your notched mortar trowel to spread thinset mortar over the marked area. Set the board down, pressing it flat to the mortar.
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3
Shoot screws with the screw gun every 6 or 8 inches around the surface of the board, straight down, making sure the screw heads are buried.
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4
Lay the rest of the boards in the first course in the same manner, setting them end to end along the wall. Use your jigsaw to cut the final board as needed.
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5
Install the second course starting at the opposite end as the first course, so the ends of the cement boards won’t line up between courses. Lay the subsequent courses in the same manner, covering the whole floor. Let the mortar dry overnight.
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6
Press mesh adhesive drywall tape over the seams between the boards. Spread thinset mortar over the tape with a drywall knife, keeping it smooth and flat. Let it set for another day.
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