How to Build a Pergola with Arch Detail

I started off laying out where the footers needed to be placed. The 8x8 pergola posts are 139 inches center to center in the front and back, and they're 100 inches center to center on the sides. I first dug holes in my yard for concrete footings. You need to look up on your local building codes how deep you need your footings to be. For my area, I need to be at least 30 inches deep. So I dug holes for a 12-inch footing tube that was 36 to 40 inches deep. For my footings, I used four 12-inch diameter concrete form tubes that I cut to the height of my footing holes. Then I placed the form into the hole and tried to level the forms between all the holes. I used my little laser level for this part, and it really helped to be a little bit later at night so I could actually see the red line. Preparing and pouring the footings made me the most nervous because I knew if I got this wrong, I would have a hard time all the way through the project. So I measured three or four times just to make sure that everything was right. For the four footings, I needed 15 bags of 80-pound concrete mix. I used my handy Harbor Freight mixer to mix the concrete, but a wheelbarrow and elbow grease work fine, too. Instead of setting the post base in concrete using a J-bolt, I opted for the 5-8-inch concrete anchors and the OWT 8x8 post bases. Plus, the ornamental post holders were pretty easy to use and forgiving for a novice like me. I re-marked the desired post outside corners and marked the base plate location. I drilled 5-8-inch holes with the rotary hammer with a 5-8-inch masonry bit. Then placed the 5-8-inch by 7-inch anchor in the hole and tapped that down with a hammer. Added the post base washer and nut. Then used the wrench to tighten down the nut, which in turn expands the anchor in place. I had to call in the muscles at this point that the 8x8s were just a little too much for me to handle solo. The OWT ornamental wood tie post bases made it really easy to set the posts on the base. However, the nut from the concrete anchor stuck up a little bit, so I had to make sure I drilled a 1-1-1-1 diameter hole about 1-1-1-1 inches deep in the center of the bottom of the post. I put a couple of the OWT plates on the sides of the post base and then placed the post on the center and secured the four plates onto the post with the included structural screws. The OWTs have this little cap that hides the screw inside the nut. Next up was getting all of the beams ready to be installed. I really wanted a pergola that had a bit of a wow factor so I used 2x12 inch beams and I cut a nice little arch shape into it. And I think that really adds to the character of the pergola. In my blog post you can print the pattern for my beams. It's printed on 8.5x11 inch paper and then taped together. There are little grey lines that help you align the pieces of paper together and you want to make sure you print it on 100% not fit to page otherwise it gets messed up. Once the pattern is taped together then I trace it onto the beam. The pattern is only half of the beam so you just flip that over to the other side and trace that onto the board. So then you need 4 14 foot beams and 10 12 foot beams. Once I traced the pattern onto the beams I used a jigsaw to cut it out. The jigsaw cut really well except I did get some blade flaring out. It created kind of an angle cut that wasn't ideal. There may be more robust jigsaws out there that wouldn't have the blade flaring but this worked and it turned out fine. So then I sanded the curve smooth with a belt sander and a random orbit sander. This really helped to get rid of those flare angles from my jigsaw. I had some surface defects on my boards so I ran them through the planer. Otherwise I would have left the boards rough cut. With pergola designs I really liked where the beams were notched together. That was just my favorite look and I knew it would be so helpful when I'm assembling the pergola to have everything notched out already. So on each of the 4 14 foot beams I measured and marked the locations for each notch. The notches are about 2 inches wide or however wide your 12 foot beams are and about 2 1 ½ inches deep. I used the circular saw and the square to make the vertical cuts and then used the oscillating tool to make the horizontal cuts and this worked out really great. My 12 foot boards varied a little bit on the board widths but I wanted to make sure the tops were level once assembled and lining up one end flush with each other. Then I clamped all the boards together and gang cut for the notches. You could continue to use the circular saw on multiple cuts to cut out the whole notch or you could use the oscillating saw to cut out the 2 ½ inch deep notch after the circular saw. Now starts the real fun, assembly. I marked up on the post 113 inches from the ground and used a laser level to make sure that it was level across all of the posts. For the upper structure of my pergola I switched over to the Simpson Outdoor Accent hardware. I just thought the style of those would just be a little bit easier for me to assemble by myself. So I mounted the deck joist ties with 3 ½ inch structural screws about 12 inches down from my level line or the width of my beam which the exact width may vary a little bit. I wanted the top of the 14 foot beam to line up with the level mark. Mounting the brackets first made it really easy for me to lift the beams in place. I placed one end of the beam in a bracket and lifted the other end into the bracket using the ladder. Once the beams were sitting on the brackets then I lined up the notches with the posts and secured the 14 foot beams to the brackets and the beams with 5 ½ inch structural screws. So once all 4 of the 14 foot beams were attached then I could move on to the 12 foot beams. So if I place the one end of the 12 foot beam onto the 14 foot beams then I could lift the other end on top with the ladder. Then I could line up the notches and drop it into place. Not all of the wood was perfectly straight and some persuasion or notch trimming was necessary a few times. So I placed the 12 foot beams on top of the 14 foot beams and lined up the notches in the beams. Sometimes this was a lot easier than others and sometimes I needed a little extra persuasion. I used the 5 ½ inch structural screws with the ornate washers to secure the 12 foot beams to the posts. I used two screws on each side of the 12 foot beams that butted up to the posts. Finally it's time to add the rafters. Start the rafters 2 inches from the ends of the 12 foot beams and then each side of the rafter will hang over about 8 ½ inches. I drilled pilot holes in the rafters before screwing them into the 12 foot beams just to reduce any cracking of the wood. Then I secured the rafters to the 12 foot beams with 3 inch exterior screws. Then I spaced the rafters about 4 inches from each other. Although the notches were a bit of work up front, it made the assembly so easy. My husband helped me to stand up the 8 by 8 beams but other than that I was able to assemble the whole rest of the pergola in a day. So it definitely helped out and it made assembly so easy. You can grab the free plans and templates for this pergola on my website hertoolbelt.com. Wood prices vary depending on what region you live in so the best way to get an accurate estimate of what this pergola would cost you is to go to the website getredwood.com and type in your zip code and it will tell you your local distributors of redwood. Then you can contact your distributor and give them your materials list and they can give you an accurate bid at what the wood would cost. Of course you don't have to use redwood, there's other woods like cedar, douglas fir, any of these would turn out beautiful. Thanks again for watching and please hit the subscribe button below. Have a great day!