I have built 5 of these swing pergolas...two at my house, one at my daughter's first home, one at her current home and one for a neighbor. It is not a difficult project to built but one that requires two sets of hands and a little muscle! And with everything, patience!!!
This is the swing today...I had to take pictures now before the wisteria bloomed...once that stuff takes off in the summer it covers the entire top and it would be difficult for you to see how the pergola is constructed! Wisteria makes a great canopy on pergolas but it is definitely high maintenance. You have to trim it a few times a year or it just goes crazy!
Okay, so let me see if I can explain how to make one of these puppies. The wood and fasteners should cost you less than $200...plus the cost of the swing. It is a two day project and you should have all the tools you need in your toolbox.
Lesson in lumber: First, lumber is notoriously crooked, warped and dinged...always try to find the straightest, best boards you can! Second, a 2 x 4 or 2 x 6 or 2 x 8 is referencing the thickness and width of the board...but it is ALWAYS 1/2" less than what is advertised...in other words, a 2 x 4 will actually be 1 1/2" x 3 1/2". Keep that in mind when measuring. The 3rd number (say 2 x 8 x 10') is the length of the board...it is accurate.
8 rebar or wood stakes
A roll of twine or yarn
4- 4 x 4 x 10 treated posts
9 bags of concrete
3- 2 x 8 x 12 treated lumber
8- 2 x 6 x 8 treated lumber (7 for the top boards, one for the center cross board the swing will attach to)
16 1/2" x 6" carriage bolts with washers and nuts
2 1/2" x 6-8" "I" bolts with washers and nuts
2 joist hangers for 2 x 6 joists
A box each of 1 1/2" and 3" deck screws
Day One: This has to be right. Screw up here and you will have a mess on your hands that is NOT easy to fix. The 4 x 4 posts need to be set in concrete and they need at least a day to set and dry before you begin actual construction.
The posts are going to be set 8' apart in the front and back and 6' apart on the sides, measuring from the OUTSIDE corners of the posts. So, you are going to create a 8' x 6' rectangle using your string and stakes. This rectangle needs to be square...measure carefully and make sure you have 8' across in the front and back and 6' from front to back on both sides. A trick to see if you're rectangle is "square" is measure diagonally across...if that measurement is the same from corner to corner, you are square. Using the stakes and string make it easy to make adjustments...just pull them up and reposition.
The INSIDE corners where the string intersects are where your posts are going to set. At this point, I found it easier to mark the corners with spray paint, pull the stakes and string and dig my holes. You want your holes to be at least 18" to 2' deep (depending on your soil) and about 1'-2' in diameter...minimum! Save the dirt!!! Once the holes are dug, restring the stakes and string, again making sure they are completely square...this is CRITICAL!!! Now, set the first 4x4 post in the ground in the front corner of the string and mix and pour your concrete into the hole...it will probably take at least 2 bags per hole...you will want to fill the hole with concrete about 2" below the ground level! NOW, MAKE SURE YOUR POST IS PERFECTLY LEVEL ON ALL FOUR SIDES (I used a 3' level for this project) Again, if you mess up here, it throws the entire project off. Use a hammer and muscle to adjust the post and make sure it is perfectly level on all 4 sides!! Now, keep in mind that lumber is not perfectly straight. But you should be pretty darn close!
The height of the pole is not important at this point...as long as you have at least 7' from ground level to the top, which you should have if you set a 10' pole 1 1/2' to 2' into the ground. The post tops will NOT all be at the same height when you set them...you will cut them later!
My daddy always taught me "measure twice, cut once." This is true of any project requiring precise measurements. So measure from the outside edge of the 4x4 post, which should be resting just inside the string corner, to the next corner in the front...it should be 8'. This is where you will set your second pole...then set the 3rd and 4th...each time, making sure that your pole is 8' across the front and back and 6' on the sides and are level. You may want to check that occasionally and make adjustments...at least until the concrete hardens up enough to keep them pretty set.
Now...leave it alone until tomorrow!!!! Let the concrete set. Until it really starts to set hard, you might want to occasionally check and make sure your posts are level.
Wood is somewhat flexible...so even after the concrete has set, you can "pull" the posts to bring them in or out a hair...but it is best if they are level and square to start out!
NOW IT IS TOMORROW! Time to start constructing the actual pergola.
I designed this so you would have to do minimal cutting.
Step ONE: Now, as you can see, I put fancy little "scroll" designs on the ends of each of the boards. THIS IS NOT HARD! Remember the little jig saw I told you you MIGHT want...this is where those nifty little tools come in handy. I use my small square to measure 1" across, 1" up, and then I used a paint can to draw a radius. Then I cut it out with a jig saw.
I used the same measurements for the ends of TWO of the 2x8x12 header board . The easiest way is to make a cardboard template, draw it on the end of the board and then cut it out with a jig saw. You will want to make a similar but smaller template for the 7 boards you will use on top (2" x 6" x 8')
Do this BEFORE you install the headers and top
boards! You might also notice that I have used a router on the edges
of all my boards to give them even more dimension...I'm trying to make
this easy on you and not blow your mind. If you have a router and know
how to use it, it looks good. If you don't, trust me, no one will
notice either way!
Step TWO: Set the front header. Put a pencil mark on the left front 4x4 post at 7'. If you have a VERY tall person in your home, you might want to set it a smidge higher but I set the top of my header at 7'. The header is 2 x 8 so that means the bottom of the header is at 6'4 1/2" (remember a 2 x 8 is actually 1 1/2" x 7 1/2")
(This is where two
hands comes in REAL handy!) Each end of the 2x8x12 header is going to
hang over the outside of the 4x4 post by about 2' on each side! While
holding the board up with the top even with the mark on the post, put a
3" screw through the header and left post. Then, use your level to make
sure the board is level, before putting a screw into the right side,
through the header and into the right post. IT IS IMPORTANT THAT YOUR
FIRST BOARD IS LEVEL!! It may not seem level if your ground has any
slope to it and if the posts are set at different heights, but you have
to use your level...not your eye! This is the board height you are
going to use as you "wrap around" the entire structure with each
board...so it needs to be completely level! Once it is level and the
two screws are anchoring it in place, put another screw in each
post...this is just to hold it up while you are putting it all
together...we will come back and put bolts in the entire thing at the
Step THREE: Take the 2 x 8 x 12' board
you did not "scroll" and cut it in half...you want 2-6' boards. Those
are your side headers. Install the left side at the same height as the
front, making sure it is perfectly level and at the same height as the
front header. Then install the back header, and the last side header.
Stay level!!!! Once the last side (the right) is installed adjacent to
the front header, it should be level and at the same height as the
front header...if it is not, the screws make it easy to make small
adjustments!!! Just unscrew them and adjust your headers so they match
up! If you have to adjust more than 1/2", you have NOT kept the boards
Once this is all done and secured with screws, you can cut the 4x4 posts flush with the top of the headers. You can a chainsaw or a reciprocating saw or a hand saw. Whatever works...honestly, you will never really notice it! Just make sure you don't hack into your headers!
Step FOUR: Install the "cross board." This is the board that your swing will attach to. Your measurement between the two side headers SHOULD be 8'. Measure the sides from the INSIDE of the 4x4 posts and mark the center of each side...inside. This is where you will install joist hangers. Secure the joist hangers to the side header with 1 1/2" screws and then set your 2 x 6 x 8' board into the hangers and then secure that with screws! I also ran 2-3 3" screws from the outside of the side header into the end of the board...just for the sake of overkill!
Step FIVE: Now it is time to set the TOP BOARDS! Again, use a template to make little "scrollies" on the ends...whatever trips your trigger. I made mine pretty identical to the header boards, but keep in mind these are 2x6 boards, so they will be a tad different. Cut each end of every board BEFORE installing!
I actually cut little "notches" in top boards where they intersect with the front and back header so they sit down onto the headers...you don't HAVE to do this...you can set them on top of the headers and then just "toe nail" screws into them. (That means putting the screws threw the top board, into the header, at an angle) I prefer cutting the notches. IMO, it just makes the structure more "sturdy." I've done it both ways so I'm not sure it makes that big of a difference! Even when I use the "notch" method, I still secure each board by "toe nailing" screws into the board and headers!
The easiest way to install the top boards is to first set the center board. Find the center of both the front header and the back header...then set the board on that mark. Make sure you are "hanging over" the same on the back and front. Basically, the center of your top boards should be right over your middle board that is set in the joists hangers.
Then I set one about 1" on the outside of each side header...then the other two are spaced at equal distances between the center and the outside boards.
Once all your boards are in place and all are secured with wood screws, it is time to put in the long bolts. Drill 1/2" holes through the headers and posts, insert the bolts and then place the washers and bolts...tighten down with a wrench or driver! Your bolts are going through a 1 1/2" thick board and a 3 1/2" thick post....5" total...so a 6" carriage bolt should work great!
you already have a swing, you can now install your "I bolts." Just
measure the distance between the arms of your swing where the
chains/hardware attaches. Find the center of the center cross board
(the board attached to the joists) and then measure from the center 1/2
that distance. Use a 1/2" drill bit to drill a hole up through the
board...this can be tricky so drill carefully and keep your bit
straight! Once you have drilled through, insert the I bolt and secure
it on the top with a washer and nut!
Fill the holes around the 4x4 posts with the leftover dirt...this is also a great place to hide rocks ;)
NOW YOUR SWING IS READY TO INSTALL!!!!