A deck adds value to your home and provides a setting for entertaining friends and family in warm weather. Before starting construction on a deck contact your local permit department. Find out what restrictions and requirements have to be followed for your area of the country. Further, contact the local utility companies to flag any underground utilities. This is for your protection and safety. The do-it-yourself handyman can create and build a 12-by-20 foot deck with a little help from friends.
Layout the 12-by-20 foot deck on grid paper. Place 4-by-4 posts every 10 feet to support the rim joist. Use the graph paper to scale the drawing to determine the material needed to construct the deck. Use 2-by-10's to span the 12-foot length of the deck.
Place 2-by-10 floor joist between the rim joist. Place the floor joist along the length of the deck at 16-inch intervals. Determine the number of pieces of decking and you can calculate the material needed to build the deck.
Grade the ground under the deck so that it drains away from the house. Place a layer of landscape fabric over the deck pad area. Place a layer of gravel over the fabric to keep the landscape fabric in place. Mark the location of the post using the graph paper plan. Drill post holes at each post location using a post hole digger. The holes need to be below the frost line so that the deck will not move due to freezing weather.
Attach a 2-by-10 ledger to the house using 3 1/2-inch lag bolts. The top of the ledger needs to be placed 3 inches below the threshold of the door. Place flashing between the deck and the ledger to protect the house from moisture damage. Make sure the ledger is level using a 4-foot carpenters level.
Fill the post holes with concrete. Set galvanized post anchors in the top of each post before the concrete has set. Let the concrete set overnight before proceeding to the next step.
Attach 4-by-4 post to the post anchors. Connect the 2-by-10 rim joist to the post using carriage bolts. Mark the outside of the deck for the joist hangers at 16-inch intervals along the entire length of the deck.
Nail 2-by-10 joist hangers to the rim joist to support the floor joist. Use galvanized joist nails to attach the floor joist to the rim joist. Cut the 4-by-4 post flush with the top of the rim joist using a reciprocating saw. The rim joist is the 2-by-10 boards that run around the perimeter of the deck.
Install the decking boards to run the long direction on the porch. Screw the decking in position using 2-inch decking screws. Use a power screwdriver for this step. Separate each row using an 1/8-inch spacer to allow for expansion of the deck boards. Start every other row with a half a board. This ensures that the end of the decking boards never align up with each other. This makes for a stronger deck. Let the last boards overhang until all the rows of decking have been installed. There needs to be a 1-inch overhang on all three exposed sides of the deck.
Place a mark at 1-inch from the outside edge of the rim joist on the side of the deck that is over hanging the rim joist. Snap a chalk line between the two marks. Cut the decking along the line to produce a professional end of the deck. Use a tape measure and a circular saw for this step.