Do you know your pergola jargon? No? I didn’t either. So let’s review: first you have your posts, or columns, which are supported by the footings. The footings are the poured concrete cylinders that the posts are either set in or attached to.
If the pergola is attached to the house like ours is, then you need a ledger board that is secured to the house. Ours is secured with Tapcon Concrete Anchors into the brick mortar.
I call the next part the joists: the additional supporting boards that tie the posts to the ledger board and form the basic frame of the pergola. I’ve also seen those called girders or beams.
The rafters form the main part of the roof. Ours are 2x4s spaced 16″ on center. The range is usually anywhere between 12″-24″.
Finally, the PURLINS, which we are working on now. The purlins are what will provide most of the shade. I just read that for the maximum sun shade, the purlins should run north-south, which I’m relieved to see, because that’s what we did (without really knowing that). So now you know too!
We’re using 2x2s for the purlins and spacing them by placing a 2×3 in between as they’re screwed down (you can see that on the left in the photo below), so that comes to about 2-1/2″ of space between each. 2x2s don’t come in super long lengths, so we have to use 2 end-to-end to span the length of our pergola. Pete cut them at a 45° angle to fit end-over-end and then screwed through both to the rafter instead of having 2 flush ends butting up to each other.
The 2x2s at Menards and Home Depot (and I believe Lowe’s as well) are a maximum 8′ long. We discovered that 2 of them end-to-end still wouldn’t fully overlap our rafters. Luckily we called a local hardware store chain called Crafty Beaver (yeah, probably not the best choice in names nowadays, but they’ve been around since the 1930s…), who had 2x2s in 10′ lengths. They have locations in Skokie and the north side of Chicago (Albany Park and Portage Park).
We bought about 45 of those and were going to combine those with the 2x2x8s that we already had from Menards but discovered that there was a vast difference in quality between the two. First of all, we didn’t have to search through the lumber to find straight pieces (and the staff at Crafty Beaver actually pick and inspect the lumber for you!). The Crafty Beaver 2x2s were also nominally bigger (the edges of the Menards lumber are much more rounded), AND unlike the Menards lumber there were no knots! Yes, they were a little more expensive, but considering the difference in quality, the price difference was minimal. I kinda wish we had bought all the lumber from them, but too late now — at least we saved a little money.
Because of the mismatch, we had to go back and buy 2x2x8s at Crafty Beaver as well. Pete has started to install those, so hopefully we’ll be done with it this weekend. We haven’t been able to fully test out the shade aspect yet, but I am LOVIN’ how it’s turning out!