Step-By-Step

1. Prefabricate the framing by fastening the notched top plate to the posts using 3-inch screws. Add two temporary cross braces so you can set the whole section into the postholes at once. Set the section in the holes, check that it is plumb and level, and attach the temporary braces as shown. Pour the concrete and trowel it so it slants away from the post, just above grade. (This keeps water from gathering at the base of the post.)

2. Build frame. Add the other 2x4 top plates to join both sections, fastening them with 3-inch deck screws. Cut 2x4 rafters so that the longest side of each measures 36 inches. Make 45-degree cuts at both ends. Join the upper ends of the rafters with angled 3-inch deck screws. Set the piece in place to check that the fit is right. Adjust as needed and fasten with 3-inch screws. Use 1-5/8-inch screws to attach the sidepieces to the 4x4 posts, maintaining equal spacing between the pieces.