Here’s a photo of all the posts in the ground. This is the same photo we used in our first blog post about this project, but we’re using it again to point out that the rear post on the right is the one Nick wired. You can see the grey cable coiled near the top of the post, and a second coil at the foot. The one on the ground is awaiting connection to the breaker box in the basement. Nick hadn’t lifted the flagstone to bury it yet.
The next step was attaching the girders. Two of them required some real work ahead of time. You’ll see that a little bit later in the post. But first, Nick asked me what kind of rafter tails I would like. This refers to the shape of the cut at the end of the girders, rafters, and slats that carry on past the dimensions of the posts. Some tails are fancy.
Some are simpler.
And some are not cut at all, or barely.
We ended up deciding on a simple angled cut. Nick figured out an angle he thought would look nice, and kept the same angle for all the rafter tails, girders, rafters, and slats.
Using a couple clamps and a 2×4 as a guide, Nick cut the tails using a circular saw he had previously given me as a birthday present. Circular saws and chocolate. It doesn’t get more romantic than that 🙂
Now Nick had some notching of girders to take care of. We wanted the corners of the pergola to be as strong and sturdy as possible, of course, and part of what would make them so would be an interlocking notch between the girders he was working on currently and the four rafters that would sandwich the posts above them later.
Here’s what Nick did. Imagine the orange piece is the girder. Imagine there are two of them, sandwiching a 6×6 post and bolted fast. Later, imagine adding the red pieces, two of them, also sandwiching and bolted to the post. Not only are the girders and rafters bolted to the post, but by nesting rafter to girder, they form a stronger joint that resists rocking and twisting even more.
Getting ahead of ourselves, but so you can see what the cross halving joint junction of post, girder, and rafter looks like later in this project, here’s a photograph of one of the corners after all four girders are fixed and the first rafter is set in place.
Nick cut these cross halving joints on the ends of all four girders and the four rafters that would be attached to the four posts. He thought having the rafters appear to set down upon the girders an inch and a half would be attractive, so each notch above would have to be half that depth, or ¾”.
He marked the girders where they would fit to the posts and marked where the notches would go on either side of the post. Also, remember that he ran the fan and light cables up the center of the wired post. In this photo you can see a reverse J hook that we’ve highlighted, drawn at the bottom of the girder, which originates at the circle in the lower center, and then carries on toward the girder top. The circle marries up exactly with the hole where the light and fan cables emerge from the post. This curved channel, which we describe routing later in this post, carries the cables away from where the bolts will pass through the girder.
Then, using a jigsaw guided by a clamped 2×4, Nick cut just the vertical cuts of the notches.
Here’s how it looks. This is the girder that will be placed closest to the house. You can see, also, the marks where Nick is going to be using his router to cut a channel for the light and fan cables to run up the post side of the girder. The channel will run between the second and third pencil marks on the right, which are highlighted below. The channel is off-center to avoid the bolts that will be driven through the center of the girders to attach them to the post.
Nick cut the notches on both ends of this girder. The next step is to take ¾” of the girder off the top, from the outside notch on the left in this picture to the outside notch on the opposite end. Nick had to use his jigsaw again to get the waste from the notches on the outsides of the girder because the table saw blade would leave a massive kerf on the underside if he had tried to use it to fully cut the waste out. But the table saw does about 95% of the removing of this long strip of wood.
This ¾” strip Nick is cutting off will be reattached to the girder in sections as he lays the cables in the girder channel he’ll cut after this step.
Here Nick has set the fence for ¾”, he’s aligned the edge of the girder with the fence, the rollers are perpendicular to the girder, and they are at the correct height to keep the girder fully supported by the table. He then holds the piece above the saw and gently lets it down for a plunge cut.
Here the saw blade emerges.
The girder was slid along the fence until the blade nearly got to the outside notch on the far end. By that point a strip of wood had been neatly separated from the girder, about fifteen feet in length.
Then Nick used the jigsaw to cut the remainder of the waste out, which also leaves two 6” pieces which are also saved for reattachment later. One of these small pieces can be seen resting on the girder in the lower left of the first of the two photos directly above. These pieces become the caps we referred to in our previous post.
Now that this long strip was off, Nick used the dado blades again to cut a ½” wide, ¾” deep groove the length of the long notch along the top of the girder. This groove will carry a light cable to the third rafter, the fan cable to the seventh, and another light cable from the seventh rafter to the eleventh.
The next thing Nick did was add an extension to the table saw fence. The girders are 11 ¾” tall when on edge, and a short fence wouldn’t provide enough support on a long pass across the dado blades.
Here’s how it’s done. Here is the fence. The holes are meant to be used to attach a board using bolts and some sort of fastener.
Here Nick is pre-drilling holes in a piece of wood that correspond to the two outside holes on the fence.
Next he attached the board to the fence with bolts and anchors, remembering to counter-sink the bolt heads so that the girders would slide flush against the fence extension and not against the proud bolt heads.
Next, Nick affixed the fence to the table and set the girder against it, clamping a 2×4 to the table to keep the bottom of the girder from sliding away from the fence as it passed over the blades.
You can see that this girder has a bow to it. There were worse examples among the rafters, some of which were also crooked as much as ¾” over 16 feet. Later, when Nick attached the braces to the girders, the girder bows were straightened out. He couldn’t do anything about the crooks, though. Later, in our post about the slats, you’ll see how much and how frequently Nick had to vary the depths of the notches he cut to accommodate these imperfections in the wood.
Turning on the saw, Nick carefully lowered the girder onto the dado blades, and began walking the girder across the table nearly the full length of the fifteen foot notch.
Next, clamping a 2 x 4 as a guide, he used the router to cut the reverse J groove up the side of the girder that will be bolted to the wired post.
The dado blades cannot cut to the very end of the long notch because the ends of the notches butt up against the edges of the table saw surface. Lifting the girder over the edge is no good because the dado blades have a much smaller diameter than a standard table saw blade, and can’t be raised high enough to continue cutting to the ends with the girder raised 3/4″ for the notch ends to clear the edge of the table. The only way to continue the channel Nick just cut on the top of the girder using the dado blades to the J groove he just routed on the side is to use a hammer and chisel and manually continue the groove.
(Hubby should have been wearing leather gloves when he did this. Tsk, tsk.)
Imagine the wired post is between you and this girder, with the light and fan cables emerging from the post on the side of the post away from you. The cables must be flattened against the post immediately as they emerge and bent 90 degrees to the left because they must now follow the reverse J channel. The cables are carried up to the top of the J channel where they are bent 90 degrees away from the post, then immediately 90 degrees again to the left to follow the channel cut along the top of the girder.
Here’s a photograph of the light and fan cables emerging from the reverse J channel after the girder has been mounted to the post. They’ll be bent toward the camera then immediately to the right to follow the channel you see here. Then the channel will be capped with segments of the ¾” strip Nick cut off earlier.
The remaining girders all had to be notched for the cross halving joints, as with this one, but only one other of them needed to have a similar ¾” strip cut off, and that one needed to have a groove cut only to the midpoint of the girder. Here’s why.
The girder at the bottom of the diagram below has to carry the light cable from the post to the third rafter, and later in the circuit from the seventh to the eleventh rafter, and it has to carry the fan cable from the post to the seventh rafter. Nearly the entire length of this girder has cable running through it.
The second girder from the top of the diagram only carries the light cable from the third to the seventh rafter, so there is no need to cut a channel the entire length of the girder as with the other one, but only halfway.
* Note: We had two electricians come by after we had done this. One said that the electrical plan was awesome and that my husband could quit his day job. The other said that he would have run power to a central junction box and then wires to the individual lights. He did, however, say that our “daisy chain” wiring was fine. And, before winter struck, we did sit out there under the lights and fan quite a few times and everything worked just fine.
So, four girders, all rafter tailed, all notched, two with long strips cut off, one with a full length groove and a reverse J cut, one with only a half length groove, all set to mount to the posts.
Next step: Setting the girders….yay!