Outdoor spaces often lack character. Inside our homes, we create ambience with paint color, artwork and furniture. In contrast, plain yards and bare patios lack a sense of purpose and feel uninviting. But you can add style, shade and visual interest to any landscape by building a pergola — a structure of columns, beams and lattice that provides shade and protection for a patio or walkway.

Common features in Italian Renaissance gardens, pergolas are an effective way to enhance outdoor living space by bringing sophistication and style into an otherwise open area. Here’s how to custom-build the perfect structure for your yard.


Planning and preparation
The top of this pergola consists of five arches that rest atop paired 2x10 beams bolted to 6x6 posts. We chose cedar for its beauty and its ability to withstand the elements. All dimensions are based on dimensional cedar (which can vary from pressure-treated lumber), so if you choose a different building material, you may need to make a few adjustments to the dimensions shown here. In addition, our project was designed to fit over an existing concrete patio. You can easily alter the dimensions to suit your needs; just be sure to make the appropriate changes to the cutting list.

Because of the multiple interlocking saddle joints, this pergola is strong yet easy-to-build. To aid assembly, many of the parts can be cut to length beforehand in your shop. This will ease some of the work: For example, though you could cut the curved crossbeams on site, it’s far easier to do so in a shop, using a flexible board as a tracing pattern (see “Creating the Curve,”).


Footings and posts
You can build a pergola atop an existing patio, but we opted to create a larger structure that required poured-concrete footings outside the perimeter of the patio. As with any project, careful measurements are key to success — if the footings aren’t square, the structure will show it.

Carefully measure and mark the centers for the four main posts (see technical drawing for complete dimensions); then dig 12-in.-wide footings at those points and pour the concrete. Local codes required that we dig to a minimum depth of 42 in.; check with your local code authorities to see what’s dictated in your area. (And of course, don’t forget to file for any necessary building permits.)

We used Simpson Strong-Tie’s RFB#4X5 1/2-in.-dia. x 5-in. retrofit bolts (see SOURCES ONLINE) to anchor the ABA66 standoff post bases to the concrete footings. Use a hammer drill to bore a 5/8-in.-dia x 3-1/2-in.-deep hole into the center of each of the cured concrete footings (photo 1, p. 20). Blow any residual dust from the holes and then fill them with Epoxy-Tie two-part adhesive (photo 2, p. 20). Tap the bolts into place and allow the epoxy to cure (the length of time depends on the ambient air temperature, as described in the adhesive’s packaging). Once the adhesive is dry, tighten the nuts to secure the post bases to the bolts (photo 3).

Cut the tops of the 8-ft. 6x6 main posts as indicated in the technical drawing (photo 4). To attach the four main posts to the post brackets, have a helper hold a post in position. Use a post level to ensure that the post is plumb; then drive 16d nails through the bracket’s nail holes as specified by the bracket manufacturer (photo 5).


Assembling the beams
Cut the end profiles and the 1-1/2-in.-sq. saddle-joint openings (positioned as indicated in the technical drawing) into the tops of the doubled-up main-beam assemblies. Lift the main-beam assemblies into place, clamp them to the posts, drill two 1/4-in.-dia holes through each of the mounting points (photo 6, p. 22) and insert 1/4-in.-dia. x 6-in. carriage bolts through the holes. Tighten the bolts; then check again to make sure that the posts have not been drawn out of plumb.

Cut the 3-in.-wide x 1-1/2-in.-deep saddle-joint openings into the bottoms and the 1-1/2-in.-sq. saddle-joint openings into the tops of the arched secondary beams as indicated in the technical drawing (photo 7). Starting at the front of the structure, lift the arched beams into place so that the saddle joints engage; then toe-screw them to the main beams (photo 8).

Just as you did for the secondary beams, cut the 1-1/2-in.-sq. saddle-joint openings into the tertiary beams. Position them above the secondary beams so that the saddle joints interlock (photo 9, p. 24), and toe-screw them to the secondary beams. Use 2-in. stainless steel trim-head screws to fasten the 31 1x3 x 14-ft. runners to the tertiary beams (photo 10, above). A scrap piece of 1x3 makes a perfect spacer to properly position the runners.


Details make the difference
Cut the four corbels as shown in Detail 2 of the technical drawing. Drill pilot holes; then attach the corbels to the main posts and to their respective secondary beams (photo 11).

To create a more elegant appearance and provide visual interest, we clad the bases of the main posts. The cladding consists of three parts: four 36-in.-long miter-cut panels fashioned from 2x10 cedar boards, four sections of 2x6 cedar base trim and four sections of 2x4 cedar top trim (see drawing).

Before attaching the panels, first apply construction adhesive to the inner faces; then nail the panels to the posts (photo 12). Note that the panels abut the standoff post bases and do not cover them. Use the 2x6 base-trim pieces to cover the post bases (inset photo, above right); then fasten the 2x4 top trim so that it rests on top of the cladding panels (photo 13­). Seal all of the miter joints with cedar-colored caulk.

Once you’ve completed the structure, coat it with a preservative and UV inhibitor to protect and enhance the cedar’s beauty. (Or if you prefer, you can leave the cedar untreated and allow it to weather to a soft gray.) Then it’s time to bring out the lounge chairs and bask in the comfort and style of your own backyard retreat.


CREATING THE CURVE
To create the curves for the secondary beams, start by marking a center line on the face of one beam. Partially drive two nails along that line as indicated in Detail 4 of the technical drawing and as shown in the inset photo at left. These nails indicate the center of the top and bottom arch. Bend the flexible board against the top nail and clamp it as indicated in the drawing; then trace along its edge (photo A). Repeat the process to draw the bottom curve. Mark the 2-in.-radius corner cutouts as shown in the drawing; then use a jigsaw to cut along the lines (photo B). Once you’ve completed one beam, you can use it as a template for the remaining four. — MB

 

Sources
Simpson Strong-Tie, 800-999-5099
Skil, 877-754-5999



Web Extra: Staining Concrete