How to Build a Covered Patio Arbor

Mark out a 3-foot-by-5-foot rectangle with chalk or a marking pencil on your porch (if you are doing this on the ground, just use a stick). This will be where you plan to set up your arbor. Use both a T-square and level to make sure you have a perfectly squared and straight-edged rectangle.

Set your four post bases into the corners of your mapped-out frame. Use your marking pencil and mark the spot on the porch where the hole rests on the inside of the post base. This will be where the anchor hole is to be drilled. Once the mark is in place, move the post base out of the way.

Drill a hole into the concrete of your porch or patio with your hammer drill. Drill four holes, one at each spot where the anchor bolt marks were made in the last step. Use a drill bit with the same dimensions as your anchor bolt, otherwise you won't be able to get the bolt into the hole. Once the holes are drilled, placed the post bases back in their positions, over the newly drilled holes.

Insert the anchor bolts into the holes and screw them into place. Use a socket wrench to tighten them and activate the mechanism inside that will secure the bolts in position.

Place a 6-foot post into the post brace. Make sure it is level, pointing straight up, 90 degrees to the ground, and have someone hold it while you hammer and nail two braces into place. The braces need to angle out from two sides of the post and be secure on the ground. Usually you can just wedge them into place at the ground, making sure that the important post is secure and remains level and upright. Do the same for the remaining three posts.

Hoist one of your 6-foot beams onto the top of your structure. Place it perpendicular to the ground and put it on top of the two posts that make up the 5-foot side of your frame. Set it on the structure so there is 6 inches of the beam hanging past both posts. Do the same with the other beam on the opposite two posts.

Drill two 9-inch holes into each beam. The hole should be directly over the posts so that when you drill down, you drill 3 inches into the center of your post as well. When finished drilling, you should have drilled a total of 4 holes.

Screw the 10-inch lag bolt into your recently drilled holes. Place a washer on the bolt before using a socket wrench to tighten it into place. Do this for all four holes you drilled in Step 7.

Place your six 4-foot rafters perpendicular to your beams. Place them so that they rest on both beams, with 6 inches of their length extending past the beams on both sides. Each of the six beams should be placed 1 foot apart. use a level and T-square to ensure they are straight.

Drill a 6-inch hole into the rafters along the plane of the beam---that is, drill completely through the rafters and 2 inches into your beams below them. Do this for every intersection of beam to rafter. There should be 12.

Place a washer on your 7-inch lag bolt and socket it into the holes you created in Step 10. Tighten it so that all connections are secure.

Place your 4-by-6 piece of plywood on top of your rafters. Screw it into place. You should screw the plywood down so that you have two to three screws into each rafter below it.

Remove your wooden braces from your four posts and apply a coat of sealant on the wood to protect it from the weather and rain. Allow this to dry.