How to Install Decking

How to Install Decking

Learn how to measure and install floor boards for a new deck. Decking is usually 2x4, 2x6, or 5/4x6 boards installed on wide faces. There are several common installation patterns. The more complicated the decking pattern, the more important it is to do a dry run before you cut boards to lay out the angles and joints. Arrange boards with the fewest possible end-to-end seams, and stagger the seams for the best appearance. Find boards that are as straight as possible and return boards that are more than a little crooked. Buy about 10 percent more decking than you estimate is necessary to allow for returns and for cutting waste during installation.

Skill Level: Beginner
Time:
  1. Step 1 Measure the Deck

    Measure the Deck

    Measure between the outside of the header joist and the house at the top of the ledger. Do this at the centre and ends of the deck to determine whether the distances are equal. Mark each rim joist at a distance from the outside of the header joist equal to the width of one decking board. Make these marks at equal distances from the house. Note: Decking installation also can begin at the house with the final board attached to the header joist.

  2. Step 2 Mark the First Board's Position

    Mark the First Board's Position
    Mark the First Board's Position

    Snap a chalk line on the marks across the rim joists. Check to make sure this line is parallel to the house. Align the inside edge of the first length of decking with the chalk line, letting the ends of the decking extend wild (at uneven lengths) beyond the rim joist. Drive two fasteners through the board into the centre of each joist. Position each fastener 3/4 to 1 inch from the edge of the board.

  3. Step 3 Install Row 2

    Install Row 2
    Install Row 2

    Install the next row of boards. Position spacers for an 1/8-inch gap. Butt each board against the spacers before fastening. If you have to use more than one board per row, centre the ends over the joists. Drive fasteners through predrilled holes at the ends of boards. Predrilling prevents splitting of the wood by either screws or nails. Boards should meet at the centre of the joist. Angle each fastener toward the centre of the joist.

  4. Step 4 Measure Again

    Measure Again
    Measure Again

    Measure from the back edge of the third row of decking to the house at several spots. Boards may vary in width so the distances may not be equal (they frequently aren't). Use a pry bar to pull a board toward the spacers, if necessary. Stick the points of the long end of the pry bar into the joist with the bar against the edge of the board. Pull on the pry bar to force the board against the spacers.

  5. Step 5 Put Crown Toward Previous Board

    Install a slightly bowed board with the crown edge against the previously installed board. First position one end of the new board against the spacers. Drive two fasteners at the end of the board. Make certain the board is tight against the spacers before driving the fasteners. Install fasteners in the last joist where the board is firm against the spacer.

  6. Step 6 Force End into Position

    Force End into Position

    Spread concrete sand over the slab, let dry, if necessary, then work it into the joints by brushing in all directions. Remove the excess sand. Repeat the two previous steps if necessary. If, after a few days, some joints are not properly filled, repeat the procedure. We suggest setting aside a number of slabs for replacement.

  7. Step 7 Lay Out Notch Around Post

    Lay Out Notch Around Post
    Lay Out Notch Around Post

    Insert spacers along the remaining length of the board, force the far end into position, and attach it to the joist. Then drive fasteners at the remaining joist positions.

  8. Step 8 Put Cleat on Post

    Put Cleat on Post
    Put Cleat on Post

    Install a 2x4 nailing cleat to support the edge of the notched board. Make the cleat from pressure-treated wood for durability. Test-fit the notched board, enlarging the notch, if necessary, by trimming small amounts of material with a jigsaw or chisel. Then attach the board with fasteners driven into joists and nailing cleats.

  9. Step 9 Put in the Last Board

    Put in the Last Board
    Put in the Last Board

    Measure the space at both ends of the last row and rip the last board to fit, if necessary. Rip the board 1/4 inch narrower than the measurement to leave an 1/8-inch gap between the board and the siding to prevent trapping moisture. Crosscut the board so it will be flush with the rim joists on both ends. The last row can't be cut in place because the wall prevents a saw from completing the cut. Use the end of the last decking board (that was cut to length before installing) and the corner of the deck at the header as reference points and snap a chalk line between them. Trim the decking on the chalk line with a circular saw. Set the saw to the proper depth so it goes through the boards.

What You Need for This Project

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