One of the easiest and fun projects you can build! Typically a standard size pergola only requires 4 posts, 2 girders and rafters. That’s it. It’s just four posts and some boards, but a pergola must stand plumb, level and square through all kinds of weather.
There are several options with pergola builds:
- Kits (sam’s club pergola kit) – this is a great option for those that don’t have many tools and aren’t experienced with building.
- DIY Cedar wood- durable but VERY expensive
- DIY treated lumber – my preference and choice.
Local laws require setbacks from a property line to the edge of a structure. Check building codes; at least 4 feet is typical. Also verify the build with your HOA (if you have one) and contact the local authorities to see if a permit is necessary. Codes don’t specify spans for pergolas because they don’t support weight.
I assume many of you will build a freestanding pergola in your backyard. I’ll give you a quick tutorial of a standard 12×12 (covered area) below. If you are connecting yours to a house or putting over a deck, message us for more details, these can get a little tricky depending on size of your deck, house layout and such.
- Draw up your plans – decide where you want it, is the ground level?, how big do we want it?, where is the sun rising and setting for shade purposes, etc. If you are working with unlevel ground, I suggest doing to ground prep to level out the area before building.
- Decide how much wood you need and go purchase it. I STRONGLY recommend staining your lumber in a garage or covered area BEFORE construction, this will save you a lot of headache.
- Standard PRESSURE TREATED materials needed and recommended: (4) 6x6x12 posts – total of $120, (4) 2x10x12 girders – total of $48, (9) 2x8x12 rafters – total of $72, 2 gallons of your favorite stain – $45, (8) 9″ carriage bolts, nuts and washers – total of $40, Box of 3″ nails/screws – $12, (3) bags of quick setting concrete – total of $9 Total of $350 completed! This is less than HALF the price of the kit and much more durable. – Optional equipment: auger (rent for $50 at sunbelt or Home Depot, Framing nail gun and air compressor HIGHLY recommended, chainsaw, borrow one from a good neighbor 🙂 (other recommended tools, drill, hammer, level, builder’s square)
- CALL BEFORE YOU DIG! – For the love of God, do not dig and electrocute yourself over a pergola. In NC, you can call 811 and the will be out within 72 hours to mark your utilities.
- After your utilities have been marked, grab some spray paint and go out to mark your posts. Your posts need to be exactly 8 ft apart from one another and DIRECTLY in-line with one another. If your posts aren’t “square” the pergola will look bad and likely fall apart – read here on how to ensure your posts are square using the Pythagorean theorem:
Drive a stake(Lowe’s stakes) into the ground where the first post of the pergola will be placed. Measure from the stake to where the second post should be placed and drive the second stake into the ground. Repeat for the third and fourth stakes so you have a square or rectangular layout for your pergola.
Tie the string around the first stake, run it around the other three stakes and back to the first, forming a square or rectangle. Tie the string off on the first stake.
Make a mark on the string 3 feet away from the first stake in one direction and 4 feet from the stake in the other direction. The diagonal measurement between the two points should be 5 feet, which creates a right angle. If it is not 5 feet, the corner is not square and you can adjust the positioning of the other stakes to achieve the 5-foot measurement. Mark and measure at the remaining three corners to ensure they also are square.
- Dig your posts: I suggest renting an auger in NC if you have girly hands or you have tree roots, dry clay in your yard. If you want to do it the good ol’ manly way, grab your post holes diggers and start digging. Whichever way you choose, I suggest digging 3 ft deep, filling your holes with a little gravel for drainage, set your posts and pour your water and concrete into the holes and put the posts in accordingly. While setting your posts, grab a 4ft. level and make sure you are PLUMB on both sides.
- Let your posts sit for 24 hours, they will not be all level due to different dig depts, measure your shortest post, then take a saw (chainsaw works best for these large posts) and level them out to the shortest post.
- After your posts have set, grab your girder boards and a strong friend. Measure and mark your girders 2 ft. from both ends ( you want your girders to stick out 2 ft on both ends). Next I recommend making some nice angled cuts for visual purposes – make yourself a stencil from spare wood and use this on all boards. Here are some examples, we kept ours simple
- Mount your girders to the post with the help of a friend using screws at first and lining up the ends with the the 2 ft. marked lines you measured earlier. Next you want to carefully drill holes for your carriage bolts using at least a 10-12″ long bit with diameter slightly larger than your carriage bolts.
- After you mount your girders on both sides of your pergola, you only have to mount your rafters! I chose to space mine 16″ on center starting from each end of the girder. You can cut notches to place on the girders or just angle nail them like I did using a nail gun. Make sure to cut your angle or design on each end before you begin!
- That’s it! It is optional but recommended to prevent warping and bowing of your rafters to mount some additional strips on top using a roof nailer or brad nailer.
- The final and most important step is to drink plenty of cold beers under your new pergola after completion.
With any project, it is important to plan and walk through the project several times before you start. Take your time, plan accordingly, measure twice, cut once, and stop for the day when you are tired or frustrated.
Below are some stages of our build. This was much more complex since we were building on an existing deck and it was 28 foot wide! Had to get creative with measurements and lumber but the finished product came out great! If anyone wants details on this one give us a shout.