Building a pergola is a wonderful way to add value to your home and your life. Pergolas are instant gathering places and provide a beautiful boost to the exterior of your home. In order to build a pergola, of course, you will need to install the pergola posts. This article uses the post brackets that you have already installed and will show you how to mount your wood posts to those secure brackets.
Before you install your posts (this example uses 6×6 cedar posts, rough cut), you want to make sure their surface is smooth. These rough cut posts will benefit from being run through a planer to make them smooth and take stain easier and better later on.
Run the posts through a planer carefully, taking off just enough of the post to create a smooth surface but not more than that.
Because a 6×6 post (these are 10’ in height) is heavy, it’s a good idea to set up some roller supports, both in the front and the back of your planer, for weight help.
One person can guide the post into the planer, and a second person can help to pull the wood out of the planer. Keep track of the sides that have been planed, and rotate your posts evenly as you plane the sides so that you maintain an even square.
One benefit of using a planer on your pergola posts is that smooth wood exhibits the gorgeous wood grain better than rough sawn wood. These variations in the wood are beautiful.
The end goal of planing your posts is two-fold: (1) create smooth surfaces on all sides of your post, and (2) ensure it fits snugly into your bracket. These 6×6 posts were actually 6” square in their rough-cut state; the bracket only accommodates 5-1/2” posts. Although the posts were smooth and even early on in the planing process, they had to continue through the planer several times in order to lose 1/2” and fit into the bracket.
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. These were stained prior to being installed, which required them to be cleaned off so the stain would be absorbed by the post itself.
After the stain has dried completely, you can install or mount your pergola posts. Pick one post and set it into your bracket, which has been positioned and installed in concrete.
Position the post on the bracket so that it aligns with other posts or deck lines, as appropriate for your building project. At this point, you need to always have one person supporting the post; it is not safe to leave it freestanding without being secured into the bracket.
Check the post for level. There will be some give in the “leanability” of your post 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 as close to a level position as possible, it’s time to begin securing the post to the bracket.
To give the post initial support, use the screw holes in your bracket to temporarily attach the post. Be sure to use exterior-grade screws, 2-1/2” recommended.
Once the screws are installed on the bracket edges on both sides of your post, it’s time to predrill holes for your lag bolts. Recommended are 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.
Always use a washer when installing lag bolts in your exterior construction projects.
Use a ratchet to tighten the lag bolts one at a time.
It’s a good idea to tighten lag bolts in opposition to each other. These bolts were tightened from 1-4, in that order.
With your pergola post screwed and bolted into place on its bracket, it is now safely freestanding.
Repeat this process for any other pergola posts you’ll need. In this instance, the far corner needs a pergola post.
In some instances, you may need to dig out some ground or grass in order to install the lag bolts and screws into the post. This isn’t a problem for grass; simply remove it in large chunks, keeping the soil and grass as intact as possible. Replace the grass as quickly as you’re done working in this area.
Congratulations! With your pergola posts installed on their brackets, you’re ready to move onto the upper pergola frame. It should be stated that you’ll want to install your pergola frame as soon as possible so the postsaren’t subject to forces that will make them wobble.