If you have your pergola posts in, your pergola frame installed, and your pergola rafter lumber stained, you’re probably ready to move onto finishing up your wood pergola by installing the rafters. In this tutorial, we will show you how to install pergola rafters quickly, relatively easily, and inexpensively – without brackets.
Metal brackets are a popular and excellent material to use when building a pergola. The brackets are graded for outdoor use, and they hold the lumber in place securely and safely. However, because brackets are required for use on each end of each board, they do not provide a clean, modern aesthetic.
Of course, construction isn’t all about aesthetic appeal – you want the finished product to be as safe and secure as it is stylish. That’s why this method is a win-win. The installation of each rafter is fast, the connection is secure, and it will last as long as the bracket method…but for much less cost.
Before you begin installing your pergola rafters, you’re going to want to find center on your perpendicular frame boards.
If you have a center beam, as this pergola does, you’ll want to find center on each side of the beam. Unfortunately for us, our center beam boards are a bit bowed. This will be a problem if we try to install rafters to a center beam that’s not straight. So, our first order of business is: straighten the center beam.
At the center point on the wall-mounted frame boards, we quickly installed a (temporary) screw eye. Tip: To install a screw eye, simply get it started into the board with your hands, then use a screwdriver through the eye to tighten it. We chose the center point because we will be installing our center rafters first, and the rafter will completely cover the screw eye hole once the eye has done its job and is removed.
Once the screw eye is fully secure into the center of the wall-mounted frame, you can hook one end of a ratcheting strap into the screw eye.
The other end of the ratcheting strap will loop twice (it’s only shown once here, but you’ll want to do twice) around the center beam, just slightly off-center, then hook to itself. Be sure you’re not wrapping the strap around the part of the beam that the rafter needs to connect with.
The setup will look like this. Now begin ratcheting the strap tight, which will pull the center beam straight. You’re going to need to watch this center beam closely; you don’t want to overtighten, as that will cause the opposite problem. Don’t be afraid of a little creaking or complaining of the wood when you tighten this up.
You can see here how the center beam is completely straight now.
Here’s a top(ish) view. The ratcheting strap will hold the beam until the first rafter, on the right-side section here, is installed.
Measure, at your center marks, from the inside edge of your frame to the inside edge of your center beam to determine the length of rafter you need. Mark, then cut this length with a miter saw.
You are going to use the HD kreg jig to drill two holes per end on your rafter board. Tip: This is hard to do alone. The jig is going to want to kick out from under you as you drill.
Have a helper place his/her foot up against the end of the HD kreg jig to hold it against the end of your board.
Press down firmly with one arm as you drill your pocket holes. This secures the HD jig into place, both from the end of your board and onto the face of your board.
Drill two pocket holes, each about 1” away from the sides of the board, onto each end of your rafter. These pocket holes should share the same face of the board so that one side of your pergola rafters looks like they’re floating.
Grab your right-angle kreg clamp for the end of your rafter that you’re connecting to a floating frame board.
At the center mark (these should be marked as lines on the top of your frame boards), with your pocket holes facing the “back” side of your pergola, use the right-angle kreg clamp to hold your rafter board in position. Using HD kreg screws (2-1/2” heavy duty pocket screws that are rated for outdoor use), attach your rafter to the frame.
Tip: After you’ve screwed in one HD kreg screw, remove the clamp. Use a level or a right-angle triangle to determine how perpendicular your rafter is. You might be surprised that eyeballing it can be quite off from square (at least, I was surprised), depending on what other factors play into your peripheral vision. Square up the board, then install your second HD pocket screw.
Repeat the process for the second side of your first center rafter, making sure everything is square and level and flush.
Tip: Hopefully everything will align perfectly, but if you have to choose, line up the bottom sides of your rafter + frame boards, as this is what will be visible. The top part of your pergola won’t be all that noticeable, in general. Use a scrap board and hammer to create a flat connection on the bottom ends of your boards, if necessary.
Here is a photo of the first center rafter fully installed. Those HD pocket screws are so strong; this rafter is as sturdy as can be.
Remember how your pergola still has the ratcheting strap attached to its center beam? When this strap is removed, we noticed that the center beam pushed still outward ever so slightly, which affected the precise straightness of the outside frame boards as well. So, to maintain a straight center board until both center rafters were installed, we simply removed the screw eye from center and repositioned it 10” (at the next rafter placement), and repeated the ratchet strap attachment and tightening until everything was straightened up again. This allowed us to easily install the second center rafter onto a squared-up frame and center beam.
Here, both center rafters have been installed, and the ratchet strap is ready to be removed for good.
The center beam is perfectly straight after the strap is removed, which means the outer frame board is straight as well. Everything is square, which is the perfect position from which to move forward in installing the rest of the pergola rafters.
From the center marks of all perpendicular frame boards (including the center beam), we used a simple ruler to mark 10” spaces, as our rafters were to be installed at 10” center-to-center.
You can see, from this “front” view of the pergola, that the rafters are seamlessly connected to the framing. We love the floating, minimalist look, especially when the two-tone pergola provides enough visual activity.
Now that your center rafters are installed, you will follow these same steps to install the rest of the rafters. Work from the side of the rafter that has the pocket screws for easiest installation.
Here, you can see how all the pocket holes line up, visibly from one side. The aren’t actually that noticeable, especially up high on your pergola. However, the insides of the pocket holes will need to be stained later on for wood protection.
And here is a view of the “floating” slats. We recommend that you install one or two rafters on one side of your center beam, then switch sides and install one or two on the other side of center, rather than installing all the rafters on one quarter of your pergola before moving to the other side. This will ensure that everything stays in line and on track.
After you’ve completed installing the rafters from your center rafter’s pocket hole side to the outer frame, you’ll notice that you’re halfway done. As long as the rafter positions have been clearly marked on the tops of your frame boards and center beams, you can jump to the top of your pergola and begin installing rafters from the outside in (toward center).
It’s not impossible to install the rafters with the pocket holes on the inside (which is why 10” or greater spacing is important), but it’s much easier to work in a larger space that a bigger air gap provides.
So don’t feel like you have to work in the direction of center rafter outward. This isn’t necessary. Once the center rafter is installed, do whatever works best for you with the other rafters’ installation direction.
Here, you can see that we’ll eventually have only a 10” air gap to work in on the rafters closest to the center rafter
But for the installation of all other rafters on this second half of the pergola, we’ll have plenty of room to move around in. This is helpful for measuring, marking, fitting the board, leveling it, clamping it, and ultimately screwing it into place.
You’re going to want two people up on ladders, one on each end of your rafter boards, at all times. Because there are no brackets in place, this method requires that one person securely holds one end of the rafter while the other end is being installed. It’s definitely not a one-person installation opportunity.
When all the rafters are installed, take a minute to step back and enjoy the results of your hard work.
With 2×6 redwood rafters, spaced 10” apart, there is plenty of shading opportunity while still providing a nice view of open sky, which makes pergolas so distinct (and, arguably, preferable) from completely covered patios.
Be sure, as you’re installing the second rafter of each line, that you align the rafter ends to create a “straight” line, even though it’s actually two rafters separated by a center beam.
If, for some reason, a rafter ends up being installed 1/4” off its center marking (hey, things like this happen in real life, right?), it’s probably more important to try to align the second rafter end with this slightly off-center one, or at least split the difference, than it is to perfectly align the second rafter with the center marking and have a visual “split” between the two halves of your rafter line.
When you compare this straight center beam with the bowed, curved original, you will see why it’s so important to get that taken care of from the very beginning of rafter installation. Don’t think that your rafter boards themselves will straighten out a doubled-up center beam.
Later, we will be taking off the tips of the pergola posts and capping them so they don’t swell or split, but for now, the pergola posts extend upward about a foot or so from the top of the pergola. If you like this look, consider your pergola work done.
The two-tone nature of this pergola is one of our favorite features. You’ll notice that there are no cross-boards (slats) on top of the rafters, as is sometimes the case with pergolas. This is because we wanted a clean, streamlined, and minimal look for this contemporary pergola, and the 2×6 rafter size provides plenty of shade potential without having to add another layer of visual busy-ness.
Even against the house, installed onto the wall-mounted pergola frame, the black and the natural stains look well together.
While two-tone furniture and architecture has been around for a very long time, it is every bit as relevant today as it was in decades (or more) past.
Of course, a monotone wood pergola is beautiful in its own right as well. In all black, this pergola would make quite the dramatic statement.
All these slats, if they were stained black like the pergola frame, would appear to be a solid roof, at least from certain angles.
You can see here the final result of the pocket holes, visible from the back side of the pergola but not terribly noticeable. Much less noticeable than metal brackets would be, which was what we ultimately wanted.
We hope you found this tutorial on how to install pergola rafters helpful. As an FYI: Many people refer to the main pergola boards as rafters (as we have done in this tutorial) and to the perpendicular shade boards often placed on top of the rafters as slats (there are none of these in this tutorial). Others refer to all the boards as slats.
Either way, enjoy finishing up the top of your pergola. It’s a beautiful feature that will add immeasurable value to your life and to your home.