How to Place Treated Lumber Directly on Concrete
- 1). Lay your lumber across the concrete where you intend to position it. Mark the outline on the concrete with a piece of chalk.
- 2). Set your treated lumber on a pair of saw horses or other support. Drill pilot holes in a line down the center of the board every 8 to 10 inches with a ¼-inch drill bit. Countersink the pilot holes in the board slightly to make sure the screw heads will run flush with the face of the lumber.
- 3). Set the board in position on the concrete and weigh it down with a cinder block or other heavy object to keep it from shifting as you work. Drill through each pilot hole in the board to mark the concrete for pilot holes with a 3/16-inch rotary mason's bit. Drill into the concrete 1/8 inch in each position.
- 4). Set the board aside. Drill a pilot hole in each marked location with a 3/16-inch rotary mason's bit to a depth of 1 ¾ inch. Wrap a piece of tape around the bit 1 ¾ inches from the tip to mark the depth. Blow the dust from the pilot holes.
- 5). Position the board with the pilot holes lined up. Drive one 3-inch concrete screw through each pilot hole in the board into the pilot hole in the concrete. Drive the screws all the way in until the heads of the screws are flush with the face of the board.
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