Dig four post holes at the corners of a rectangle that is 10 by 14 feet. Dig the holes 3 feet deep, and wider at the bottom than at the top. Put the 12-foot-long 6-by-6s into the holes and pour 3 inches of pea gravel around the base of each post. Prepare two to three bags of concrete mix in the wheelbarrow and pour it into the holes up to within 3 inches of the top.
Prop up the posts, brace them and use a level to ensure they are vertical and squared with each other with sides parallel. Allow the concrete to cure for 24 hours before putting any stress on the posts or attaching cross-members.
Screw two 16-foot 2-by-8s to each pair of posts that are 14 feet apart. The top edges of these main support boards should be even with the tops of the posts. Screw the support boards to the sides of the posts with 5-inch galvanized screws. The ends of the supports should extend a foot beyond the posts. Do the same with the other pair of posts so you have two long parallel sides. Pre-drill 7/16-inch holes through the ends of the long support beams into the posts and screw in 5-inch-long half-inch lag bolts.
Cut the 6-foot-long 6-by-6 into two equal pieces for swing supports. Select which side you want the swing on. Place the 6-by-6s lengthwise between the front and back 2-by-8 cross-members so the centers of the two support boards are 8 feet apart and 4 feet from the ends of each set of cross-members. Screw the 6-by-6s into place with 5-inch-long galvanized screws. Drill a half-inch hole horizontally through the cross-members and the supports and bolt with 10-inch carriage bolts for added strength. The 6-by-6 supports will bear the weight of the swing.
Set a 12-foot 2-by-8-inch board on edge across the top of both sets of cross-members 1 foot from the end. Screw the board in place with 5-inch-long galvanized screws; pre-drill the holes at a 45-degree angle through the boards and into the top of the cross-members. Place seven more 12-foot 2-by-8s two feet apart down the length of the cross-members.
Stain the pergola assembly with an outdoor stain and sealer with a brush or garden sprayer according to manufacturer's instructions.
Pre-drill a 7/16-inch hole in the bottom center of the two 6-by-6 supports you installed in the main support beam for the porch swing. Screw in the half-inch eyes and attach the porch swing assembly.
Things You Will Need
- Post-hole digger
- 12 bags of concrete mix -- 80 pounds each
- Pea gravel
- Shovel, wheelbarrow and water hose
- 4 pressure-treated posts, 6-by-6 inches by 12 feet
- Socket set
- Drill and screwdriver bit
- Half-inch drill bit, 10 inches long
- 7/16-inch drill bit, 5 inches long or more
- 4 pressure-treated boards, 2-by-8 inches by 16 feet
- 1 pressure-treated post, 6-by-6 inches by 6 feet
- 2 carriage bolts, 1/2 inch by 10 inches long
- Galvanized screws -- 5 inches long
- 8 pressure-treated boards, 2-by-8 inches by 12 feet
- 8 lag bolts, 1/2 inch by 5 inches
- Circular saw
- Tape measure
- Speed square
- Wood stain/sealer and brush or sprayer
- 2 half-inch screw-in eyes
- Porch swing kit
- Safety glasses
- For shade, train ivy or climbing vines such as wisteria to grow on the pergola framework.
- This framework will carry two swings. Simply install a second pair of supports at the other end of the pergola's long side and hang a second swing assembly.