How to Build a Pergola

Basic Backyard Pergola

Field Outdoor Spaces / Flickr / CC BY 2.0

Pergolas that adorn yards and gardens always capture attention and elicit compliments. Interlaced with trailing plants like fragrant jasmine and wisteria, colorful bougainvillea and honeysuckle, pergolas shade pathways and patios, acting as a kind of second garden above head. Classic pergolas often extend for miles, shading pathways for horseback riding or strolling. Most residential yards do not have enough space for lengthy pergolas. When adapted for the realities of today's yards, a pergola can be any partially-roofed open outdoor structure that is longer than it is wide. Simple to build, this basic garden pergola measures about 8 feet wide by 16 feet long and requires only low-cost materials and minimal carpentry skills.

Permits, Zoning, and Utilities

Your pergola might require a building permit if it falls within certain size or structure-type criteria for backyard structures. Exterior structures also typically cannot be built within a certain distance of property lines. Consult your local permitting office for guidance. Call 811 to have local utility companies visit and mark the location of buried services.

Tools and Supplies You Will Need

Instructions

Mark the Dig Points for the Posts

On a flat, level section of ground, establish a rectangular pattern of six points where you will mount the vertical posts. With the hammer and wood stakes, mark three points in a straight line, each 7 feet apart. Now 7 feet away, mark another three points in the same manner parallel to the first line. Use a chalk snap line or twine to ensure that each set of three points is straight.

Set the Posts

With the post hole digger, dig 3 feet down or below your area's frost line, at each of the six staked points. Scatter a bed of crushed gravel about 4 inches thick at the bottom of each hole. Set one post in each hole, first tamping down the gravel with the post. Hold a post so that it is plumb, then pour dry ready-mix concrete around the post. Fill the hole with water. Nail two pieces of scrap wood per post in a tripod fashion to hold the post plumb while the concrete cures.

Level the Posts

While your posts may end up being the same height, it's expected if they vary by an inch or two. With the laser level or a chalk snap line and bubble level, establish a uniform height for all of the posts. Use the lowest post as the measurement to which the other five must conform. With the circular saw, cut down any of those five posts as needed.

Shape the Top Beams

Cut one end of each of the two-by-eights in any decorative fashion that you choose. The easiest way to do this is to make a straight 45-degree cut with the miter saw. For a more graceful look, cut the end as a quarter-circle with a jigsaw. Cut one end only. The other end of each board must keep its 90-degree factory edge.

Mount the Top Beams

Place the two-by-eights at the top of the vertical posts, one on each side. You will have a total of eight two-by-eights, with the eight decorative ends facing outward. After drilling pilot holes, affix with 3-inch screws, using four screws per attachment point. This will comprise a total of 16 screws per board, eight on one side, eight on the other side. It is helpful to temporarily hold the two-by-eights in place against the posts with clutch style bar clamps or trigger clamps.

Cut the Lattice Decorative Ends

Nine two-by-sixes will rest on top of the beams and will be perpendicular to the beams. Similar to the two-by-eights, cut decorative ends on each two-by-six. The difference is that you will be cutting both ends of each two-by-six.

Notch the Lattice Two-by-Sixes

For a flawless look and a tighter fit, notch the two-by-sixes so that they can rest on and within the two-by-eight beams. Create two notches at each end, each notch 1/2-inch deep. Use the jigsaw to cut out the notches. After cutting the notches for one two-by-six, test it at various points down the length of the beams. If it works, use this as a template for cutting the eight other two-by-sixes.

Build the Top Lattice

The two-by-sixes and the one-by-threes will form the top lattice. Rest the notched two-by-sixes on the beams, perpendicular to the beams and spaced two feet apart from each other. Lay the one-by-threes over the top of the two-by-sixes, spacing them 1-foot apart from each other. Lay them perpendicular to the two-by-sixes in a grid-like pattern. Screw down the one-by-threes with the 1 1/2-inch screws, using one screw at every place where the two boards cross.

Secure the Lattice to the Beams

While the lattice is sufficiently heavy to remain in place by itself in good conditions, a strong wind is capable of upending it. With the cordless drill and 1-inch galvanized screws, secure the lattice to the one-by-eight beams with stainless steel hurricane ties.

Pergola Building Options

Lumber Alternatives

Buying pressure-treated lumber helps your pergola last longer and reduces maintenance duties. Ground-contact pressure-treated wood is the least expensive type, but it is speckled with injection points where chemicals have been forced into the wood. You may wish to spend a bit more for appearance-grade pressure-treated lumber which has no visible injection points. Cedar lumber, about twice as expensive as the ground-contact boards, is a favorite exterior building material for fences and gates. It will attractively weather to a gray, silvery color if left untreated.

Paving Under the Pergola

Lay stone or concrete patio pavers below the pergola and around the posts. For a smooth appearance, miter pieces of one-by-fours at 45 degrees and nail around the base of each post as trim.

Changing the Pergola's Dimensions

This pergola takes full advantage of 8-foot-length boards, resulting in very little wasted wood. However, you can change the proportions of the pergola in any way you choose. For example, you can create a long, narrow walkway pergola by cutting the upper two-by-sixes in half, thus halving the pergola's width. Add more two-by-eight beams, vertical posts, and one-by-threes to add as much length as you wish.