How to Build a Deck Over Concrete
- 1). Measure out your deck on the concrete slab. Decide how far it will extend over the concrete and then determine where to place your deck supports. There should be a support at least every 8 feet, and if possible, one every 4 feet.
- 2). Make marks on the concrete with a can of spray paint to show where the four corner posts for the deck will go.
- 3). Measure again to ensure an exact position of the corner posts, and draw a 4 x 4 inch square on the concrete for the post.
- 4). Position a 4 x 4 inch square bracket on the concrete slab on your mark. With 2-inch concrete screws, fasten the bracket to the concrete using a hammer gun. A nail gun powered by a bullet cartridge is the best method. Repeat this step until all the post brackets are installed.
- 5). Cut your deck posts to size and position them in the brackets so the sides of the bracket are flush against the post beams. Secure the beams to the brackets using wood screws and a power driver.
- 6). Frame your deck posts with 6 x 2 inch beams, attaching them to the posts using 1/4-inch bolts. Then lay your deck boards onto the frame, just as you would build any other deck.