How to Install a Freestanding Pergola

PERGOLAS turn a flat, sun-baked patio into a destination. Beyond the immediate shade they provide, they define an outdoor room, pulling the architecture of your home into the landscape. Done well, a pergola feels permanent, intentional, and sturdy enough to weather years of high winds and seasonal shifts. Building one is less about fine carpentry and more about geometry and gravity. The secret lies in the squareness of your footprint and the strength of your anchor points. If your base is level and your posts are plumb, the rest of the build is simply stacking lumber in a way that respects the structure's weight.

1. Square Your Footprint First. Measure your desired footprint and mark post locations with stakes. Use the 3-4-5 triangle rule to ensure every corner is perfectly square before digging.
2. Anchor Posts Plumb and Deep. Dig post holes at least 24 inches deep and 10 inches wide. Set your 6x6 posts, fill with fast-setting concrete, and use a level on two adjacent sides to ensure they are plumb while the concrete cures.
3. Level the Beams Perfectly. Cut two long beams to length and bolt them to the top of your posts using structural lag screws. Ensure the beams are level with each other across the entire span.
4. Space and Tie Rafters Tight. Space your rafters evenly across the beams, typically 16 to 24 inches on center. Secure them using metal rafter ties for a wind-resistant connection.
5. Crown the Grid with Purlins. Lay perpendicular purlins across the rafters to create the final roof grid. Fasten each crossing point with exterior-grade screws.
6. Seal Against the Elements. Apply a high-quality exterior wood stain or sealer to all surfaces. This prevents moisture rot and protects the wood from UV degradation.