How to Build a Wood Truss Porch Awning

Make two marks with a marker on the side of the house. Make a mark on both outside corners of the porch. If the porch is longer than 10 feet, make a third mark on center between the two outside corners, allowing for a third post to increase stability of the structure.

Mount a 2-by-6-inch ledger board on the side of the house at the desired height for the porch awning, usually 8- to 10- feet high; connect as many boards as needed to cover the length of the porch. Secure the board with a lag screw or bolt on one end, level the board, add a second bolt, then secure with two more bolts at the other end. When both ends are level and secure, add two more bolts every 4 feet.

Install a U-shaped mounting base in each of the outside corners of the porch; these bases screw into the porch floor, eliminating the need for post holes. If buried posts are required, dig 3-foot holes, add about 6-inches of gravel and pack the gravel to provide a stable foundation with sufficient drainage.

Insert a 4-by-4-inch post into the U-shaped mounting bases and secure with a screw through each of the guide holes in the bracket. If you must dig a post hole, insert the post into the hole, fill the hole with wet concrete and allow to harden. Brace the post with a 2-by-4-inch board while the concrete hardens; insert a screw through one end of the 2-by-4 and into the post, then wedge the other end of the 2-by-4 into the ground so that it doesn't slide.

Drill a 1/4-inch pilot hole through the tops of the posts, about 3 inches from the top. Drill another pilot hole through the center of each end of a 2-by-6-inch board.

Connect the 2-by-6-inch board to the posts with carriage bolts inserted through the pilot holes to created the outside ledger for the awning. Have a second person hold the board in place on the inside of the posts while you tap the carriage bolts through the holes and secure with washers and nuts.

Connect the two ledger boards with a system of 2-by-4-inch board trusses, using your choice of joist hanger brackets or hurricane brackets. Install the bracket to the ledger boards first, inserting screws through the pilot holes in the bracket, then set the board inside the bracket and secure with screws through the bracket and into the board.

Stretch the fabric awning over the wood trusses and secure with your choice of staples or grommets. Staple the center on all sides first and work toward the edges, pulling the fabric taut as you go. Covering each staple with 100 percent silicone sealant decreases the chance of leaking and rusting around the staples.