Oct 25 , 2018
I sized the pergola for small gatherings of family and friends. With an eye toward daytime comfort, I spaced the roof slats to block some sun but still let in enough rays for warmth.You can build this project in about two weekends if you have an agreeable helper. I spent just under $1,300 on materials. The concrete floor, which is optional, added another $500. Your floor could be flagstones, paver bricks or even a ground-level deck.
Big, but not complicated
If you think this pergola is beyond your skill level, take a closer look. It takes time and muscle, but it’s really just a bunch of standard lumber parts screwed together. The trickiest part of the job—positioning the posts—is almost goof-proof with simple plywood plates (see step 3). Most sheds and even fences are more complicated than this project!
Survey the site
Be sure you have a fairly level spot in your yard. Slopes can be subtle and a bit deceiving, so bring a level attached to a long, straight 2×4 out to the yard as you check site locations. Our site sloped by about 3-1/2 in., which worked out well. I made sure the slab would be just above the grade of the yard at the higher end, which then left the lower area as a “stepping off” the slab point. If you have a challenging yard, you may need to level an area by first terracing with a short retaining wall.
Prep the site
If you’re building in a grassy area, you’ll need to remove the turf. You can rent a kick-style sod cutter, but if you’re over 22 years old, you’ll probably agree that renting a gas-powered sod cutter for $60 a day is well worth the cost. You can remove the sod in less than two hours and still have a good chance of getting out of bed the next day. If you don’t have a spot that could use fresh turf, make plans to get rid of a full pickup load of sod. Plus: Check out this other amazing structure you can build in your backyard, plans included!
Mark out the perimeter
You’ll need to mark out a perfectly square layout for the posts. Cut the sod away and mark the perimeter of the pergola with stakes and string. To start, position two strings exactly perpendicular to each other using the 3-4-5 triangle method (in this case, your measurements will be 9, 12 and 15 ft.). If you’re not familiar with this trick, search online for “345 triangle.” Once you get two lines squared, the other two will be easy. But double-check your layout with diagonal measurements before you mark the posthole locations (shown in step 2). Check the layout by taking diagonal measurements; equal measurements means the layout is square.