Attaching the Slats

All the really hard work had been done by this point.  From here on out what remained, after cutting the slat ends to match the rafters and girders, was simply the tedium of measuring and marking and sawing and chiseling each of the notches in each slat, fourteen notches per slat, fourteen slats.  That’s a total of 196 notches that needed cutting.

Here Nick is mounting the first of the slats.  If you look closely you can see that the depth of each of the notches is about the same.  That worked out all right as, where the rafters were attached to the girders the tops of all the rafters were all about level.


Toward the middle of the rafters, however, due to the imperfections in the lumber that we’ve written about before, the slat notches varied considerably in depth.  Nick wanted the notch to meet up with the top of the rafters as closely as possible.  He was able to do this by first laying the slat flat across the rafters, then eyeballing (estimating) how high above or below a level line from the first to the last rafter each of the middle twelve rafters rose or fell because of a crook.  Then he increased the depth of the notch for rafters that crooked above the mean and decreased the depth for those rafters that fell below the mean.  What we ended with was a wide variation in notch depth.



The distance between each slat in a pair needed to match the distance between each rafter in a pair, so Nick used the same 5 ¾” wide blocks for this step that he’d used previously.



Though the distance between the pairs of slats was less than the distance between the pairs of rafters, because we were fitting fourteen slats into a 14’ span, and an equal number of rafters into a 16’ span, because the boards in each pair of rafters and slats were all 5 ¾” apart, the intersections of the pairs of slats and pairs of rafters produced perfect squares when looked at from above or below.



Nick used three spacer blocks to ensure a uniform distance between the slats in each pair.










Here Nick is drilling the last galvanized deck screw of the project.  The only things left to do were to apply some silicone caulk to the places where rain might get into the light fixtures and fan, and wire the switches and receptacle.



Now, for the finished project…




And how it looks almost 2 years later.



In the background you can see the potting table that we made out of reclaimed pallet wood.



And a night shot.



This is , without a doubt, our favorite place to be as soon as the weather in Wisconsin is even remotely close to warm.



Phase 2 will be an outdoor fireplace to the right of the patio, where the kitchen garden is now.  We’ve collected some bricks from an old school house that, sadly, burned down a few years ago. The city has given us the go ahead. Now we just have to motivate ourselves to begin.

Hope this helped anyone who is considering or in the middle of tackling a project like this. It’s definitely worth the time and energy!

Attaching the Lights and Fan

After rough wiring the pergola, the next step was to attach the light fixtures and fan.  When Nick finished our basement he acquired a number of handy tools that might or might not ever be used again.  Here’s a picture of a tool that’s been used several times since.  It’s used to make a slice along a length of electric cable, like the UF cable Nick used to wire this project.  We think it’s called a ripper, and if any of our readers are Australian, that’s exactly what we think of it.




Here Nick runs a cable through the ripper.  Notice that he had previously cut the UF cable down from their longer lengths to the approximate length that would fit in the light fixture.



You’ve got to get a real grip on the ripper when pulling it down the stretch of cable, but even though Nick had had experience with this tool he seemed to get bit by it time and again when he got to the end of the cable and the halves of the ripper snapped together.  Nasty little blood blisters galore.  Here’s a tip: wear gloves.



Here are several wires stripped of their cable coverings.



Here Nick is using another tool acquired for the basement project to further cut the wires to length.



There’s a wire stripper feature to the wire cutter in the photo above, but the non-ground wires in the UF cable, in addition to their black and white insulation, have another layer of clear plastic over them that proved too slippery for the wire stripper.  The stripper would separate the insulation from the end ½” of the wire, but couldn’t bite through the clear plastic casing.  Nick remedied that be scoring the plastic with his knife, then using the stripper he removed the end ½”.


Here’s what the wires look like prepped to attach the lights.


From some of the wires he’d shortened Nick took lengths of ground wire and using a needle nosed pliers put a couple of curves in them for attaching to each light fixture.



Using a carpenter square Nick made sure each light fixture was 2” up from the bottom of each rafter,


he marked where each screw was to be drilled,



and attached the base plate of each light.


If you’re a professional electrician, or even just a handyman who does a lot of wiring, the problem with the setup in the photo above will jump out at you.  Later, when the lights and fan were all attached, Nick had a friend who owns an electrical contracting business come over to attach the feeder cable from the wired post to the circuit box in the basement.  Nick explained to him how he’d mounted the lights, and after Nick had explained the process, and after his friend had complimented his wiring plan and execution, the professional suggested that we should have nevertheless made the base of the lights fire-resistant by having some sort of metal plate between the rafter and the light base plate.  What Nick did was leave wood exposed to any arcing that might occur if his connections should ever fail.

So, we’ll explain the correction Nick made a little later in this post.  The attachment of the lights explained in this post is still good, though. ** Just be sure before you build your own pergola with lights that you read all the way to the bottom where we explain the right way to enclose the light bases.**

So here Nick is shortening the wires that are part of the fixtures.


And stripping them.


Using waterproof silicone filled nuts Nick wired the lights.  Have a rag handy.  The silicone gets messy really fast.


Then bending the wires to fit the spaceDSC_1049

Nick attached the covers.


And here’s the (nearly) finished installation.  Notice how the strip of wood that Nick removed to install the cables, then re-attached, is barely noticeable.


Next came the fan.  As you can see from the following photograph the mounting bracket came with an integral metal plate, so this fixture was good to go when installed the first time.

Using a couple of ladders and several pieces of waste wood to support the fan hub, Nick wired the fan.  This photograph clearly illustrates the overhang of the base that was necessary because the fan base exceeded the space Nick wanted to maintain between the rafters, and later the slats, throughout the project.  Remember that he had routed depressions in rafters 7 and 8 to accommodate the extra width of the fan base.




Here’s the fan all wired up.  Notice the hole in the base cover at the bottom of the photo.  There are two holes through which the mounting screws are set into the base.  We selected a nice wet-rated Hunter Fan.  The only complaint I have with it was that the fan only comes with two mounting screws.  What’s the cost of a third screw?  The photo after this shows the cost of not having a third screw.


By the time we were finishing this project August had turned to mid-October and Nick’s fingers were getting a little stiff.  When he was aligning one of the two screws with its hole it slipped out of his fingers, falling to the patio below, which is made of flagstones of extremely irregular surface.  The screw, being light, bounced unpredictably.  In the end, when it was found, we discovered it had bounced about ten feet.  It took Nick and three of our kids about 45 minutes to cover just about every square inch of our patio looking for that screw.  So that was the cost of not having a third screw.  Nick would gladly have paid another few bucks for a fan with an extra mounting screw if he could have avoided this waste of time.


Here’s the fan ready for the blades.


Nick, attaching the blades.  Note how close the top of the fan hub comes to the bottom of the rafters.  To be within code the fan blades had to be 7’ 2” from the patio.  That’s the reason we had to recess the fan base.  With the recess the blades met code.  When designing the pergola we wanted the top of the slats that lay across the rafters to be below the level of a kitchen window that overlooks the back yard.  If that limitation had not been part of the design process we could have made the entire pergola six inches taller and simply mounted the fan to mounting blocks attached to the underside of the rafters.  But I like how Nick did this.


OK, back to the light fixtures and the steps necessary to make them safe.  Here’s a metal electrical junction box cover.  It’s the same diameter as the light bases that are screwed to the rafters.  Nick had to drill three holes through these covers, one to let the screw that mounts the light cover to the base through, one to let the screw that attaches the ground wire to the base through, and the largest hole to let the incoming and outgoing wires through.  The last light on the circuit only has incoming wires, though.


This is a drill bit designed to go through metal.  As you can see, it’s stepped, with diameter indicated for each step.  These are expensive.  Nick spend about $35 for this bit, but it was the only tool for the job.


The plate clamped to a work surface.


Drill bit at the ready.


Nick had marked the location of each hole using a light base as a template, and having determined the necessary diameter for each of the three holes, began to drill.


The first hole was for the mounting screw.


The second was for the ground wire screw.


The last hole was for the wires, and had to be wide enough for the clamps Nick used to ensure a snug and safe passage for the wires through the sharp holes.





Nick removed each of the lights, then passed the wires through the plates, clamping them in.


Here Nick has re-affixed the base plate to the rafter.  The wiring is no longer exposed to wood.


Attaching the lights proceeded exactly as described earlier in the post.


Next post: Attaching the slats.

Pergola Post VII: Setting the Rafters, Part 2

The first four rafters have been mounted to the posts, and of the remaining ten three required special handling, which we explained in the prior post. Now Nick was ready to begin wiring those three rafters and mounting them with the rest.

Remember the cables emerging from the wired post need to be set into the groove that had been cut in the first girder. Nick had laid the cables into the groove prior to mounting the second rafter. Here’s a photo of how that looks. He put some silicone caulk around the groove between the rafters to prevent water from getting into the channel from that point.


Here Nick has placed the 6” cap over the girder between the rafters and nailed it down. Later he would caulk the ends and post side of the cap for watertightness.


Here the fan and light cables continue in the groove from under the second rafter.


Remember that Nick had removed a strip from the top of the first and third girder to serve as a cover for the wires set in their respective grooves. As the wired rafters were set, Nick cut these strips into smaller pieces to cover the girder grooves as he progressed. In this photograph Nick is checking the fit of the girder cover from the second to the third rafter. Next he’ll carefully nail the cover down, with galvanized nails. The wire that is lying outside the groove will be going to the first light, which is on the third rafter. The fan cable is still lying in the groove. In Patio Pergola Part II we wrote that Nick left about ten feet of cable to run to the first light and twenty feet to run to the fan from where the cables exited the post.


Here the third rafter has been set on the girders and the light cable had been fed up into the groove on the bottom of the rafter. Using deck screws fed into pre-drilled pilot holes to avoid splitting, the 6” cap has been reattached to the rafter, between the first and second girders, after the cable was fed into the rafter groove. Behind the cables is the butt end of the cover that Nick is fitting in the photograph above, which extends about ½” beneath the rafter. The fan cable continues on in the girder groove. The second section of groove cover will also slide about ½” into the cavity from where the light cable enters the rafter.


Here are two photographs of the light cable fed through the rafter groove and emerging from the chamber of the first light fixture.



Next Nick ran a section of cable from the first light location to the second, and then from the second location a length of cable sufficient to reach the third light, which will be located on the seventh rafter. You can see that the incoming cables enter the first hole we wrote about at the end of the prior post, while the outgoing cables exit from the second. Nick made certain to leave enough cable emerging from the rafter to wire the light fixtures. That’s kind of important.


In this photograph the groove cover was reattached to the bottom of the rafter, again with deck screws set in pilot holes. There’s not much room for error here. The rafter is 1 ¾” wide, and the groove is ½” wide, leaving only 5/8” on either side of the groove to take a screw, preferably closer to the edge than the middle. Nick clamped the strip on and then drilled the pilot holes and then removed the strip to check that the holes were a safe distance from the wires.  Nicking the wires is something to definitely be avoided.Setting rafters 7

The cable from the second light exits the third rafter and enters the third girder the same way it entered the rafter from the first girder, snaking from one groove to the other. Here Nick is nailing the cover running from the third to the seventh rafter. He had previously attached the section of the third girder groove cover from the second to the third rafter. At the end of this section of girder cover the cable will bend up and enter the seventh rafter.

The non-wired rafters, numbers four, five, six, eight, nine, ten, and twelve simply sit on top of the girder covers. There was no need to segment the covers further as the only reason for splitting the covers was to permit a wire to pass from girder to rafter or rafter to girder.

Nick used deck screws to reattach the covers on the bottom of the rafters because those covers are hanging from the rafters, but he used galvanized nails to reattach the covers to the girders because they are simply resting on the top.


Here is the third rafter completely installed, with covers reattached to both rafter and girder. The seam between the covers and the rafter and girder can just barely be seen. When the electrician who connected the wired post to the circuit box looked at the lights and fan with no apparent wiring to deliver power he was impressed. That made Nick feel pretty good.

Setting rafters 8

The seventh rafter was prepared just like the third, except that on the side of the board opposite the lights, at the center, a single hole was drilled up from the groove, and a cavity to pass the fan cable through was chiseled. The eleventh rafter was prepared and wired like the third, except, as mentioned previously, no second hole was needed for the sixth light.

Jane wanted the rafters, and later the slats above them, to form a sort of checkerboard pattern. Getting ahead of ourselves as we’ve done several times already, here’s how that turned out.


The rafters and slats had to be a consistent distance apart. To get a uniform distance between the two boards that comprised each pair of rafters and slats, Nick used a piece of scrap from the angle cut at the end of a brace as a spacer. That’s the chunk of wood resting on the top of the brace two photos above. The space between the boards comprising the pairs of rafters and slats is the same, therefore, as the space between the first and second rafters, and the thirteenth and fourteenth, which sandwich 6” x 6” posts, which are actually 5 ¾” square.

Some algebra was necessary to determine the spacing between the pairs themselves. Now when ever any of our kids complain about math class and say, “When will I ever use this stuff in the real world?”, we just point out the window!    As you will recall, the dimensions of the pergola, without considering the cantilevering overhangs of the girders, rafters, or later slats, is 14′ x 16′. Starting with the 16′ length for the rafter spacing calculation, the distance from the outside of the first rafter to the outside of the fourteenth is the sum of the distance from the outside of the posts, 16′, plus the combined thickness of the two rafters, 3 1/2″, or 16′ 3 1/2″. There are seven pairs of rafters, and six spaces between these seven pairs. So the equation is:

7x + 6y = 16′ 3 1/2″

We know that x represents the width of a pair of rafters, which is the distance between them, 5 3/4″ plus the combined thickness of the boards of the pair, 3 1/2″, for a total of 9 1/4″. Y is the distance between the pairs, which is what we’re trying to determine.

Converting 16′ 3 1/2″ to inches we get 195 1/2″. So

7(9 1/4″) + 6y = 195 1/2″
65 3/4″ + 6y = 195 1/2″
6y = 195 1/2″ – 65 3/4″
6y = 129 3/4″
y = (129 3/4″)/6
y = 21 5/8″

The distance between each pair of rafters and the next pair was 21 5/8″. Using the same math later for the slats, and the 14′ length, the distance between pairs of slats was 17 5/8″. These distances give the nice checkerboard pattern above.

Nick had to work with pieces of lumber that were imperfect. Here’s one of our rafters.


When pieces like this were mounted they retained their curve.

Setting rafters 9

By using a bunch of clamps, however, Nick was able to straighten these rafters before they were screwed down to the girders. Screwing them down once they were clamped straight forced them to stay straight, or much straighter than they were. When Nick set the slats later, their 1 ½” notches further held the rafters true.

Setting rafters 14


At this point Nick bought a Hunter wet-rated ceiling fan. The base of the fan was 6 1/2” in diameter. This posed a problem, as the spacer Nick had been using was 5 ¾” wide, consistent with the dimension of the four posts. He considered his options, the first of which was to simply make the space between the seventh and eighth rafter wide enough to accommodate the fan base. You’d be surprised, maybe, how noticeable a 3/4” deviation from the norm can be. As Nick said, that option was a non-starter.

Nick got out his router again. On the insides of the seventh and eighth rafters, prior to screwing them down, he routed a 4” x ¾” depression ¼” and 1/2″ deep, respectively, in the center of each, just below where the fan cable would emerge from the chiseled-out cavity in the seventh rafter.

Then, from a length of 2” x 6” cedar Nick cut two pieces measuring 5 ¾” x 5 ½” x 1 ½”. In one of these pieces he routed a ½” wide by ¾” deep groove from the center to the middle of one of the 5 ½” edges. Then he drilled a 1/2” hole through the center of that piece. Next, above the routed depression on the seventh rafter, he clamped this piece tightly, the side with the groove toward the seventh rafter, and then drove two deck screws from the opposite side of the seventh rafter into the clamped piece. Nick then fed the fan cable from the groove in the first girder into the seventh rafter, then up the hole into the cavity in the rafter then through the groove in the mounting block he’d just attached, and then down through the hole, and after that he placed the second 5 ¾” x 5 ½” x 1 ½” piece atop the first and screwed them together from the top using four deck screws at the corners, and drove two more screws from the opposite side of the seventh rafter into the second mounting block.

Now he mounted the base of the fan according to the instructions provided, so that the edge of the base just touched the bottom of the 1/4″ depression he’d routed in the seventh rafter. This left 1/2” of the base overhanging the opposite 5 ½” side of the mounting blocks he’d just attached to the seventh rafter.




Next Nick set the eighth rafter without screwing it down. He’d need to move it later to attach the fan to the base. The depressions he’d routed allowed the overhanging fan base to fit, the mounting blocks were perfectly flush with the eighth rafter, and the space between the seventh and eighth rafters measured exactly 5 ¾”.

Nick continues to set the remaining rafters.

Setting rafters 10

Next post: Attaching the lights and fan.

Pergola Post VI: Setting the Rafters, Part 1

The fourteen rafters were the next stage of the pergola. Each of these rafters would have its tail cut at the same angle as the girders. Ten would have four 1 1/2″ notches cut into them to settle down onto the girders. We preferred the look of the rafters settling down onto the girders rather than simply resting atop them.

Remember that the other four rafters that sandwich the posts were only notched ¾”, and together with the ¾” notch on the girders formed the cross halving joint we wrote about previously. To get the location of those notches precise, Nick set the rafters on top of the girders, into the notches he had previously cut in them, and marked the location of each rafter notch, then took the rafters down, cut the kerfs, and chiseled out the waste on the ground. Nick learned after a few rafters that it was more efficient to cut and chisel the lumber aloft, and easier on his back.

Here he is marking one of the rafters for a cross halving joint.


Nick used my jig saw to create these kerfs.


Chiseling out the waste, with gloves on.


On the grass awaiting a lift.


The four rafters on either end of the pergola were the first to be attached. Here, Nick is getting the first one up and in place.

Setting rafters 2

Here’s a close up of the cross halving joint that gives so much stability to the corners.

Setting rafters 3

At every step we wanted to ensure each timber was level.

Setting rafters 5

After the first two rafters were set about the first pair of posts, Nick attached them with a couple of bolts, one per post. He didn’t give any thought to the aesthetics of using only one bolt per pair of rafters per post versus two, as with the girders. I think it looks nice, and with the braces attached later to the rafters, Nick tells me sturdiness is assured. Another reason we used only one bolt per post to attach the rafters was because we had already bought all the ½” x 10” galvanized bolts in the Madison market. There weren’t any left, and wouldn’t be for another two and a half weeks. We were on a bit of a schedule so waiting wasn’t really an option.

* After one of the worst winters on record with insane winds, cold and snow, the pergola is none the worse for wear.

Setting rafters 4

The second pair of rafters, on the opposite side of the pergola, went up in the same manner. Here’s what the first four rafters look like after they’ve been mounted and their braces have been attached. The brace that required lag screws instead of bolts is above Nick’s head. You can see the light, fan, and receptacle boxes attached to the back side of the post.

Setting rafters 6

Each of the remaining ten rafters would be notched 1 ½” four times to settle on the girders. There was no need to carry through with cross halving joints on these ten, so the notch was the full depth, not ¾” as with the first four rafters mounted about the posts. Three of these remaining ten rafters required special handling, similar to the two girders that carry the cables.

The three special-handling-necessary rafters required long 1 1/2” lengths cut out, as was done with the girders, this time on the bottoms rather than on the tops, with the long strips similarly saved for later reattachment. These long strips had to be cut from the outermost notch of the house side end of the three rafters to the innermost notch of the rafter on the end toward the yard, creating, in addition to a strip about 13’ long, a small 6” “cap” from between the two house-side 1 1/2″ notches, which together, the 13′ length and the 6″ cap, will cover the entire groove cut and chiseled in the rafter bottoms carrying cable from the wired house-most girder over the non-wired girder and then on to the lights and fan. Here’s an image of the wiring plan, which we provided in one of our earlier posts, to remind you how the cables are run through the pergola.

Wiring scheme

So, after removing the 1 1/2″ x 13′ and 6″ sections, a groove on the underside of each of the three rafters would be cut with the table saw and dado blades to run the cables through. As with the first girder where it attached to the wired post, a hammer and chisel would be required to complete the long groove on each side of the first two wired rafters, but only on the end of the groove closest to the house on the third, because, as the light circuit terminates with the sixth light, there is no need to continue the groove past that light.

Jane had seen some photos of illuminated pergolas while looking for examples of designs for our project and noted the type of light she wanted. We discovered some by Nicor Lighting called Single Cylinder Bullet Spot Security Lights, and purchased six in bronze, two for each of the three wired rafters.

Nicor Lighting Bullet Security Light image

After Nick had removed the long strips and caps (that 6” part of the rafters which will cover the cables between the two house-side girders), and cut the groove in the underside of the three rafters as far as the table saw would allow, and extended the grooves to the end of the long notches using hammer and chisel, the three rafters needed some additional work.

Nick wanted to have the center of the lights located three feet from the inner girders and centered also from top and bottom of the rafters, remembering to incorporate the 1 1/2” strip he had removed. He marked the location in pencil, and then using a ½” bit drilled two holes, starting inside the grooves on the bottom of the rafters, to the midway point of the rafter width, one hole for the cable entering, one for the cable leaving. He then chiseled a gently rounded edge to the holes where the cables would be entering and emerging to avoid making them take sharp 90 degree turns.


Next Nick drilled two holes 7/8” deep (half the 1 ¾” thickness of the rough-cut board) from the side of the rafter on which he would mount the lights to intersect with the holes he had drilled from the bottom, then using hammer and chisel he cleaned out a chamber that would allow the cables to be snaked in and out. He followed this process for five of the six lights. We only needed one hole for the last light on this circuit because there would be no cable coming out.



Nick also used this process for wiring the fan, except, like the last light in the circuit, there was only one cable coming into the fan, so only one hole was drilled.

Next post: Setting the Rafters, Part 2.

Patio Pergola Part V: Setting the braces

You might remember when we wrote about all the lumber we’d bought to build this pergola we mentioned the 10 foot 6 x 6 posts that Nick needed to cut into five foot lengths. A 12” compound miter saw would have been perfect for the job, but we only have a 10”. Cutting the posts in half wasn’t a problem. Nick just cut as much of the wood with the 10” as he could and then rotated the piece and cut again until he’d cut entirely through.

Things got complicated when he had to angle cut, though. The braces need 45 degree cuts on both ends, which because of the limitations of our saw required rotating the wood, angling the saw, and beveling the saw as well, several times on each end of each 5 foot brace. And yet, with a little patience and care, Nick was able to get all his cuts to fit like this.

Of all the photos we took of this project Nick likes this one most. He’s pretty proud of these cuts. He still recommends a 12” saw, though.

Setting braces 20

To set the braces Nick clamped each at the top, and then placed a couple clamps on the post just where the bottom of the brace would be placed. The brace rested on the bottom clamps, and were held fast by the top.

Here’s a photo of the setup, but here he was just determining fit. You can see that he’d angle cut the bottom of the brace, but the top still needed cutting. You can’t see the bottom clamps, but they’re there. Still hadn’t cut the notches for the cross halving joints at this point, as you can see. Once again, they’re easier to cut when the girders are on saw horses than mounted to posts.

Setting braces 1

After both ends of the brace had been angle cut, Nick was ready to start drilling. Here Nick is using the hole saw to start the first bolt hole on the first brace he set.

Setting Braces 6

Next he chiseled out the hole. He’d already chiseled out the first hole, and here he’s working on the second. You can see how he used the clamps in this photo.

Setting braces 12

Next Nick used his 1 1/2″ spade to deepen the hole, then the auger bit to drill through, and finally the hole saw once again, and chisel on the post side of the hole, to recess the nut and washer. Here’s what the two ends of the bolt look like. You can also see that after being bolted the brace fits to the post precisely.

Setting braces 13

Setting braces 14

We used 10” bolts for the top hole and 8” bolts for the bottom. In retrospect Nick says he would have used a 12” on top and the 10” on bottom. The holes wouldn’t have needed to be as deep. Even still, there’s about 9 ¼” of wood being compressed between the top bolt head and the nut on the other side, and 7 ¼” for the bottom bolt, still a very strong joint.

Next, using a straightedge, a ruler, and a pencil, Nick determined where he wanted the bolts to pass through the upper part of the braces. They lie on the centerline of the brace, 3″ from the top and bottom. No real math involved. He just wanted the bolts far enough from the edge of the girder that the girder wouldn’t split if a gale was blowing, but not so close that the bolts would offer only limited resistance to a rocking motion.

Setting braces 15

Nick was really challenged angle cutting these braces precisely given the limitations of a too-small saw, but there was no way we were going to drop $300 for an average quality 12” compound miter saw we would only need for 16 cuts on this project (two 45 degree cuts per brace, two braces per corner, four corners).

A few notes about the following picture. You can see a bit of the knee brace above the near girder, behind hubby’s hand. This is because of the ¾” thick strip he cut off the top of the near girder, which will, when reattached, serve as the cover of the groove he cut for the light cable which will run from the second to the third light on the circuit. Though the groove only needed to be cut half way, Nick took the strip off entirely from the inside notch on one end to the inside notch on the other, not from outside to outside as he’d done on the first girder.

On the first girder, the cables emerged from the post between where the first pair of rafters would be located and the groove needed to be cut from where the reverse J cut led the cables out to the top of the girder. So a groove had to be cut between the rafters on the first girder, requiring a cap, hence the need to extend cutting the long strip all the way to the outside notches. Nick didn’t need to cut the 6” cap off the far end of the first wired girder. He realized only afterward that doing so was unnecessary.

On this side of the pergola the light cable would come into the girder from the third rafter, nearly two feet beyond the post, so there was no need to take off the caps at the ends of this girder. You can see it still attached, above the bolts. As with the second girder mounted on the first two posts, the second of these two girders did not require any special cutting besides the four cross halving joint notches.

Setting braces 17

At the end of our previous post we showed you a photograph of this girder with a really noticeable bow in it. After attaching the braces, here’s how it straightened out.

Setting girders 43

One thing concerned Nick about these braces. Well, actually only about one of them, the one he would attach later on to the two rafters that sandwiched the wired post. The bolts would pass through the post, but the fan and light cables run directly up the center of this post, exactly where the bolts would pass through. He wondered how it would look, with all bolts on the three other corners all on the center line, if he had to pass the bolts for this one rafter brace hard to one side to avoid the cables. Neither of us liked it conceptually, and we would have hated it in practice.

Then Nick remembered how useful lag screws are. The heads of the screws look just like the heads of the bolts, and they would still form a really sturdy connection. So he carefully measured how deeply he could drive his auger to remain shy of the cables, 1” deep in the far side of the post, wrapped his bit with masking tape at the depth he did not want to exceed, and using his hole saw, spade, chisel and hammer created the holes, then with his auger drilled away to the safe depth.

Setting braces 26

Here are a couple photographs of how the first four braces turned out. By the way, in the first photo you can see the long notch from the ¾” strip of wood Nick took off to cap the channel for the light cable.

Setting girders 45

If you look closely at the following photograph you can see the four ¾” notches cut for the cross halving joints with the rafters.

Setting girders 42


Next Post:  Preparing the Rafters

Patio Pergola Part IV: Setting the girders

Because the girders were so heavy, Nick couldn’t rely on clamps to support them while he was preparing to drill the bolt holes through them and the posts, so he clamped some 2×4’s to the posts, leveled them, and screwed them in to create shelves on which the girders would rest, and then be clamped. Here Nick is leveling the first of two 2×4’s on the wired post before temporarily fastening them with deck screws.

Setting girders 1

When we set the posts in the ground we ensured the tops were all level with each other. (See Post 1) Nick wanted the tops of the posts to be flush with the tops of the four rafters that would be sandwiching them later, so he had to ensure the tops of the 2×4 supports were all equidistant from the tops of the posts, 20” down. This distance represents the actual height of the girders, 11 ¾”, plus the actual height of the rafters, 9 ¾”, less the 1 ½” depth of the cross halving joints that we described in Post III. Here’s a photograph of how, after careful calculations, measurements, cutting, and mounting, the rafters do end up flush with the post top. It was taken after the slats had already been set.


Here Nick is clamping the first girder, resting on its 2×4 support screwed to the second post.

Setting girders 3

Next he checked that the girder was level, and it was.

Setting girders 4

And here the first girder, clamped loosely to its posts, awaits the guiding of the light and fan cables through the reverse J channel described in the previous blog post.

Setting girders 2

Here Nick is working the fan and light cables into the channel on the side of the girder. Once that was done he could clamp the first girder tightly against the post, set and clamp the second girder, and drill the bolt holes.

Wiring girder 2

After emerging from the post and running up the J channel routed in this girder, here are the cables for the lights and fan. They will be bent directly toward the camera, and then immediately to the right to lie in the channel cut along the top of the girder. The channel will later be covered by pieces of the ¾” strip Nick previously removed from this girder using the table saw. (Post III)

Wiring girder 3

Here Nick is setting another 2×4 support, ensuring that it is level in both horizontal directions.

Setting girders 5

Setting girders 6

Here both 2×4 supports are set and screwed to the posts, both 20” down from the post top, ready for the second girder. Nick removed the clamps after temporarily attaching the first girder to the posts with deck screws because he didn’t want to chance the clamps failing while he was working with the second girder and having the first one come crashing down.

Setting girders 8

Here the second girder is mounted. The next step is boring the holes and bolting the girders tight.

Setting girders 10

We bought a slew of ½” diameter, 10” long galvanized bolts with a similar number of nuts, and double the washers, cleaning out three large building supply stores in the area of the bolts. Apparently these pieces of hardware aren’t in high demand. An employee at the first one Nick emptied told him it would be two and a half weeks until they’d get another supply of them. That’s when he went to the next two stores. Nick used three 10″ bolts per corner to attach girders and rafters, and three each per brace per corner, less one for which he substituted a lag screw which we’ll detail later, for a total of 35 10” bolts. We also used seven 8” galvanized bolts and one 8″ galvanized lag screw for the braces. Incredibly, the bolts, screws, washers, and nuts represented 10% of the total cost of this project.

Rather than getting a ½” spade to drill the holes Nick opted for an auger, which worked like nobody’s business, a really great tool. To drill the holes he first used a 1 ½” spade and drilled into the wood a bit. He didn’t want the bolt heads proud, but thought that having them sunk flush would be a nice touch. Then he used the auger bit to drill the hole through. For the first several holes in this project, he used the spade again to sink the washer and nut on the opposite side, but the point of the spade was narrower than the ½” diameter hole left by the auger, and the spade initially swung wildly as he was trying to drill, making a really rough hole. Thankfully, the four holes he finished this way were on the far side of the girders above, against the house, and unobserved.

When considering how to do a better job on the more visible holes Nick recalled the hole saw he’d used to wire the post, but that was a 1” and he needed a 1 ½”. Off to the hardware store. This was not the only time Nick ran off for a single item he discovered he needed mid-stream.  We will list all the tools we used in the final post.  That way, if we’ve inspired anyone to give a project like this a try we’ll save you a bunch of time and gas.

Here’s the process that evolved for drilling bolt holes. Using the 1 ½” spade, drill a hole about ½” deep. Using the ½” auger bit, drill through girders and post (and later, rafters and post). Then, with the 1 ½” hole saw, and using the through hole from the 1/2″ auger as a guide, drill from the backside about ½” into the wood, and using a hammer and chisel clean out the hole.

Setting girders 14

Setting girders 17

It’s unbelievable with all the photos we took of this project that we didn’t get one of Nick using the hole saw and chisel on the backside of the girders and rafters, but here’s one of how they’re used on the braces, which we’ll write about in the next post. By the way, since this photo is up, using the hole saw is the only way Nick could get a decent hole in the braces while beginning at a 45 degree angle.

Setting braces 2

As you can see from the first hole, above the one Nick is working on in the photo below, the saw and chisel combination gives a pretty clean hole.

Setting braces 10

Next comes driving the bolts through and cranking down on the nuts.

Setting girders 28

Here’s the first pair of girders completed, with the cables ready for setting in the long groove atop the back one.

Setting girders 33

We really think the recessed bolt heads and nuts looks nice, and there’s still a lot of wood left beneath the washers to make the corners really strong.

You’ll notice from this photograph and the one above that there are no notches for the cross halving joints on this girder. In his eagerness to get this piece up Nick forgot to cut them before the lift. No matter. He cut the four notches with the jigsaw after it was mounted. It’s easier to do on the saw horses, though.

Setting girders 34

The process for the second pair of girders was exactly the same. Here Nick is cranking down on the fasteners of the second pair.

Setting girders 40

This photo is a little dark, but you can see another example of a bowed girder, later straightened by the braces.

Setting girders 37

Next post:  Bracing the Girders..

Patio Pergola Part III: Wiring the Girders

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.

Wired post picture

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.

Pergola with string lights

Some are simpler.

Pinterest pergola

And some are not cut at all, or barely.

Patio Pergola Idea

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.

Girder 16

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 🙂

Girder 22

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.

Setting rafters 3

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.

Girder 18 with J highlighted

Then, using a jigsaw guided by a clamped 2×4, Nick cut just the vertical cuts of the notches.

Girder 19

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.

Girder 21, highlighted to show channel

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.

Girder 23

Here the saw blade emerges.

Girder 24

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.

Girder 2

Girder 4

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.

Setup for post, girder, rafter cuts 6

Here Nick is pre-drilling holes in a piece of wood that correspond to the two outside holes on the fence.

Setup for post, girder, rafter cuts 7

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.

Setup for post, girder, rafter cuts 9

Setup for post, girder, rafter cuts 10

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.

Girder 7

Girder 9

Girder 8

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.

Girder 10

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.

Girder 11

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.)

Girder 14

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.

Wiring girder 3

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.

Wiring scheme

* 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!