How to Install a Substrate on Top of Hardwood Floors
- 1). Hammer down raised nail heads in the floor. Make sure the floor is clean, dry and free of obstructions.
- 2). Spread thinset mortar over the floor, starting in one corner of the room and using your notched trowel. Lay enough to encompass one full sheet of cement board.
- 3). Set the cement board into the mortar, in the corner. Press it firmly into place, walking over it to get it set.
- 4). Sink galvanized screws through the cement board and into the wood floor below, using your screw gun. Put a screw in every 6 inches, making sure the screw heads are sunk completely into the board.
- 5). Spread more mortar over the floor in the space at the narrow end of the first board, along the wall. Press the second board into place there, securing it with screws as before. Repeat the process, laying the boards in courses, butted against each other with their ends staggered from course to course so there are no four-way intersections. Make the necessary cuts with a jigsaw. Cover the entire floor.
- 6). Lay mesh drywall tape along the seams between the boards. Apply mortar on the tape with a drywall knife, covering it completely and getting it smooth and flat. Let it dry overnight.
- 7). Sand the mortared seams with the sanding pad and medium sandpaper, just enough to remove any high spots. The substrate is now ready for tiling, new wood flooring or any other surface.
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