How to Install Pergola Posts

Building a pergola can add value to your home and provide an outdoor living space. But, in order to build a pergola, you need to install the pergola posts.

Before getting started, install your post brackets. Then follow this tutorial on how to install pergola posts. We’ll be using 6 x 6 rough-cut cedar.

How to Install Pergola Posts

How to Install Pergola Posts - wood prep

How to Install Pergola Posts: Step-by-Step Tutorial

Follow these steps for smooth, sturdy, and good-looking pergola posts.

Step 1: Plane the Posts

Before you install your posts (this example uses 6×6 cedar posts, rough cut), ensure they have a smooth surface.

These rough-cut posts will benefit from being run through a planer to make them smooth and better able to take stain.How to Install Pergola Posts - run posts through planer

Run the posts through a planer, taking off just enough to create a smooth surface.

How to Install Pergola Posts - roller supports

Because a 6×6 post (these are 10’ in height) is heavy, set up roller supports in the front and the back of your planer for weight help.

How to Install Pergola Posts - guide the post

One person can guide the post into the planer, and a second person can pull the wood out. Keep track of the sides that have been planed, and rotate your posts to maintain an even square.

How to Install Pergola Posts - planer benefits

One benefit of using a planer on your pergola posts is that smooth wood exhibits the gorgeous wood grain better than rough-sawn wood. 

How to Install Pergola Posts - two fold

The end goal of planing your posts is two-fold: (1) create smooth surfaces on all sides, and (2) ensure it fits snugly into your bracket.

These 6×6 posts were 6” square in their rough-cut state, but the bracket only accommodates 5-1/2” posts. Although the posts were smooth and even early on in the planning process, they went through the planer several times to lose 1/2” and fit into the bracket.

How to Install Pergola Posts - smooth finish

Step 2: Stain the Posts (Optional)

Once they’re smooth and ready to fit the bracket, you have two options: (1) install the pergola posts immediately, or (2) finish (e.g., stain or paint) them. We stained our posts prior to installation.

To stain your wood before constructing your pergola (recommended), follow this guide: how to stain pergola wood.

How to Install Pergola Posts - stained wood

Step 3: Mount Your Posts to Their Brackets

After the stain has dried completely, you can install or mount your pergola posts. Pick one post and set it into the bracket you’ve already positioned and installed in concrete.

How to Install Pergola Posts - post in bracket

Position the post on the bracket so that it aligns with other posts as appropriate for your building project.

Have one person support the post – it is not safe to leave it freestanding without being secured to the bracket.

How to Install Pergola Posts - level post

Check the post for level. There will be some give in the “leanability” the higher up you go, which is good news for building a pergola. Check for level on two adjacent sides of your post.

With someone holding the post in a level position, it’s time to begin securing it to the bracket.

How to Install Pergola Posts - screw holes

To give the post initial support, use the screw holes in your bracket to temporarily attach the post. Use exterior-grade screws, 2-1/2” recommended.

How to Install Pergola Posts - screws installed

Once you’ve installed screws on the bracket edges of both sides of the post, it’s time to predrill holes for your lag bolts.

Use 1/2″ thick lag bolts, 2-1/2” in length, so they travel to the center of your post but don’t run into each other.

How to Install Pergola Posts - installing bolts

Always use a washer when installing lag bolts in your exterior construction projects.

How to Install Pergola Posts - tighten bolts

Use a ratchet to tighten the lag bolts, one at a time.

How to Install Pergola Posts - bolts in opposition

Tighten lag bolts in opposition to each other. These bolts were tightened from 1-4, in that order.

How to Install Pergola Posts - post bolted

With your pergola post screwed and bolted into place on its bracket, it is now safely freestanding.

How to Install Pergola Posts - repeat

Repeat this process for any other pergola posts you’ll need. In this instance, the far corner needs a pergola post.

How to Install Pergola Posts - dig out some grass

Pergola Posts Installation Tips

In some instances, you’ll need to dig out ground or grass to install the lag bolts and screws. If grass is your obstacle – remove it in large chunks, keeping it intact. Replace the grass chunk when you’re done working in the area.

How to Install Pergola Posts - installed

With your pergola posts installed on their brackets, you’re ready to move onto the upper pergola frame. Install your pergola frame as soon as possible, so the posts aren’t subject to forces that will make them wobble. You’ll be on your way to a completed pergola.