- May 14, 2019 at 2:26 pm #575501
Building a pergola is an easy project for many homeowners. The materials are inexpensive and the DIY project is easy to complete in a weekend. The following steps detail the basics of building a simple pergola. Customize your structure with additional decorative details.
- Wood: 6×6 posts, 2x10s, 2x2s
- Concrete mix
- Deck screws
- Tape measure
- Posthole digger
- Carpenter’s level
- Miter saw
- Circular saw
- Saber saw
Plan Your Pergola
ANCHOR SCREWS SECURE PERGOLA POSTS.
For a freestanding pergola, plan to sink posts at least 3 feet into the ground. For example, an 8-foot-tall pergola needs posts at least 11 feet long, so buy 12-footers. If possible, bolt some of the posts to existing decking posts or similar strong structural members.
Using a posthole digger or an auger, dig the postholes at least 30 inches deep or to the depth required by local codes. Shovel several inches of gravel into the bottom of each hole and insert the posts. (You will cut them to height later.)
Brace the posts temporarily so they are plumb. Use 3- to 4-foot 2x4s or 2x6s at the bottom and 1×4 or 2×4 angle braces anchored to stakes. Getting the posts both plumb and placed at the correct depth may require some shifting, but if you are off an inch or so, it won’t be readily visible.
Combine water and bagged concrete mix and fill the postholes. Work the mixture up and down with a stout stick to remove all air pockets. Overfill each hole so rainwater will run away from the post.
If your building site allows you to anchor posts to an existing structure, do so using bolts. Take time to ensure the posts are perfectly plumb.
Install Roof Beams
For a basic pergola, the frame supporting the pergola roof consists of doubled 2×10 beams. These four beams create a solid structure supporting the notched rafter pieces.
Prepare for installing the beams by cutting the posts. Mark the cutoff lines on the posts, be sure to account for the 2×10 beams prior to finalizing the height of the posts. Cut the posts with a reciprocating saw.
Measure the distance between the posts at the top and miter-cut 2x10s for the outer beam pieces. (It’s OK to bend the posts an inch or two if they are not equidistant.)
Working with a helper, place each beam piece so it aligns with the top of each post, and attach them by driving three 3-inch deck screws into each joint. Measure and cut the inside beam pieces. Laminate them to the outside beams using polyurethane glue and 1-1/4-inch deck screws driven every foot.
Build the Roof
A basic pergola roof consists of notched 2×10 lower rafters set perpendicular to the upper rafters. Generally the lower rafters are 2 to 3 feet longer than the arbor width and the uppers are 2 to 3 feet longer than its length.
The rafters often have decorative ends. Develop a pattern for your rafter ends using a freehand drawing or use a purchased or borrowed pattern. The design can be as simple or intricate as you would like.
Next, notch the rafters. For the lower rafters, notch the bottom of each end so the rafters will fit over the beams. The notches should be 3×2 inches. On top of these rafters, cut a notch for the upper rafters to fit into. Cut notches on the bottom of the upper rafters for every lower rafter. Place all rafter notches an equal distance apart.
Cut the notches first with a circular saw, then a saber saw. Clean out the corners with a hand saw and chisel. As you work check to see that the notched rafters will fit tightly together.
With a helper, set the lower rafters on top of the beams, spacing them evenly. Slip the upper rafters onto the lowers, fitting the pieces together. This requires jiggling and tapping with a hammer. Once all the pieces are put together, drill angled pilot holes and drive 3-inch deck screws everywhere a rafter rests on a beam. If the structure wobbles, stabilize it with angled braces. Finally, apply two or more coats of stain, finish, or paint to the pergola.
This article originally appeared on Better Homes & Gardens several years ago, I saved it so we could build our own pergola.