Pergola at the Lake Cabin

Written by: karl

Many years back, in the summer of 2009, I was asked if I could build a decorative pergola at the family's lake cabin. For better or worse, I agreed to take it on without a second thought.

I had a rough idea of how they were built and what I might want to do, so I fired up SketchUp and created a quick approximation to make sure that the scale and structure were going to look right.

A render from SketchUp.

I don't recall the exact dimensions of anything as I'm writing this except that the uprights are 6x6 posts. I believe the doubled beams are 2x8s and the rafters running perpendicular are 2x6s. All of the lumber used was treated.

Once I finalized the design and dimensions, I was ready to get to work. At the time of building the pergola, I lived over an hour's drive from the cabin, so I had set myself the goal of completing the entire project over two adjacent weekends.

On the first weekend, I used stakes and string to lay out the site and located where my footings were going to be placed. I dug the holes as close to two feet deep as I could manage and roughly 1 foot in diameter. I knew that I was going to use metal anchors at the base of the posts, but I didn't yet know exactly which style of anchor I was going to use. Because of this, after mixing and pouring the concrete, I ended up just smoothing the tops of my footings roughly flat.

Coming back a week later, I brought all of the tools and materials I though I would need. I started by centering of all of my posts on their respective footings, then drilling a hole with a masonry bit to accept expansion style anchor bolts. I used the bolts to attach galvanized standoff post anchors.

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  An example of the anchors used.
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  The anchors in place.

Before raising the huge posts, I located where the carriage bolts for the 2x8 beams should pass through the posts and drilled those holes. I also notched the bottom corners of my beams at a 45 degree angle for a clean and simple look.

I then used some spare wood as bracing to help me hold the posts plumb while I attached them to the anchors. Once they were all standing, I was able to add the long beams and bolt them together into standing pairs. I had pre-drilled all of the holes, but they were still a little tight and pounding the eight galvanized carriage bolts through all of that material while they were overhead was exhausting!

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  A pair of carriage bolts attach the beams to each post.
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  A simple 45 degree angle was cut into the end of the rafters.

The last thing to do before slapping on a coat of paint was to get the rafters attached. These also got a 45 degree notch on the bottom, and then additionally they all need to be notched to fit over top of the beams as well. Each rafter has 4 notches, half of their depth, to allow them to fit over the beams. They are then secured using 4" screws from the top into the beams.

A picture of the finished pergola.

And that's really all there was to it. It's certainly not the best or only way to do it - in fact I wouldn't recommend that anyone else do it exactly this way! If I were to make any changes, I think I would look into adding bracing between the vertical posts and the horizontal beams to help stiffen the whole structure.