Woodworking Plans & Projects
How to Build a Deck
STEP-BY STEP METHOD OF DECK CONSTRUCTION
Step 1
Mark off the deck area using string and "batterboards" making sure that it is square. Batterboards are boards hammered in to the ground just outside the corners of where the deck will be. See Fig 1. The string will help you visualize the size and appearance of the finished deck and will also serve as a guide for excavation and post placement. But trust me, it will always look smaller this way than when it is done.
SQUARING WITH STRING
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Attach string to house and/or batterboards to make sure its level. Use a felt tip marker to mark the string 3' from the corner in one direction and 4' from the corner in other direction.
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When the diagonal connecting these 2 points is 5', you have a right triangle and the angle at the corner will be 90°.
Note: To obtain the 5' measurement, move the string attached to batter board to the left or right until correct.
Step 2
Prepare the site. With a spade or sod cutter, remove sod to a depth of 2 or 3 ". Uncover an area approximately 2 ft. larger than the planned deck. It's unlikely that grass would be able to grow in the shadow of your deck, so you might as well transfer the sod to a bare spot in your yard where it would be useful. To prevent weeds and unwanted vegetation from growing up through the deck, spread a sheet of polyethylene film over the area. You'll have to slit this to embed posts in the ground. After the posts have been installed, cover the sheet with gravel, pebbles or wood chips.
Step 3
A ledger/header board is the next step if you are attaching your deck to an existing structure.
The placement of the ledger/header determines the level of the deck floor, so be sure it is positioned at the correct height and is horizontal.
When fastening ledger/header boards to wood, the ledger should be held securely with bolts through the wall or lag screws. Use aluminum flashing to keep water from getting behind your ledger board. This should tuck up under your siding and bend down over the ledger, then down the face of the ledger board. Where aluminum or vinyl siding is in place, carefully cut siding away from house so that ledger/header board can be secured directly to the house. You may be able to use the bottom edge pieces of the siding above the deck to refinsh the lower edge, so save these if possible. See figure 2. I will assume the joists are hung from the ledger and not resting on it, but be sure you account for the height of your deck boards when figuring the placement of the ledger. (Typically just 1 ½ inches down from the final height of the deck.)