When I first saw my house, I fell in love with the front porch that runs along the entire front side. It's huge (about 8' x 35') and the perfect spot for a porch swing.
However, I'm a hair under 6'2 and I used to play rugby so I am most assuredly not petite or dainty. When I tried to find a nice swing to put up in my awesome porch I couldn't find any that were even remotely acceptable. They were all too small, too uncomfortable, too flimsy, and just generally not right.
So, I did some poking around the internets and found several designs that had elements that I liked. I made a shopping list and one trip to the hardware store later and I had a couple of hundred dollars worth of stain-grade lumber and various bits of chain and other hardware...
Step 1: Getting Started.
This was probably the hardest part of the project. The basic criteria for the swing was that it should seat at least 3 average to large-sized adults and it should not feel flimsy.
Even though I had a general design in place, some details (like the angle between the back and the seat) were still TBD and since I didn't want to waste any of the not-so-cheap wood I bought, I did a lot of measuring and note taking. I wasn't concerned with specific dimensions as much as finding something comfortable so I looked around at various benches and seats. I
In the end the small bench you see in this photo actually contributed the angle for the back to the seat, the width came from another chair I found and the seating depth was based on the length of my own legs (that also determined its final hanging height which was noted by some of my shorter friends and family who feel a bit small on it)
Step 2: The Back Supports
These pieces required the most complicated cutting of the entire project.
Where each back support attached to the seat, I decided to create half-lap joints at the angle I wanted for the back and the seat. These were then glued and bolted together making for a fairly strong joint.
The pieces that would make up the seat also had dadoes cut into them where the main structural pieces that it would be hung from would slide in.
Step 3: Porch Swing Skeleton
Here you have the skeleton of the porch swing mostly in place.
I dado-cut the pieces that ran lengthwise in the seat (those would be what it hung from eventually) and those slid into place nicely with the l-shaped back/seat pieces. I pre-drilled some holes and screwed each of those points together for extra stiffness. Then it was just a question of adding the top and front pieces and screwing everything in place without screwing anything up.
Step 4: Slat Installation
Before I started permanently attaching the slats, I test fit them and the armrests.
When I was happy with the arrangement, I started attaching them. This part seemed to take forever since I was pre-drilling every hole. I used a convenient spacer to keep all the slats evenly spread out.
This part was very much a lather, rinse, repeat kind of step. Very easy, but very tedious.
Step 5: A Dry Run
After all that effort, I decided to lug the (surprisingly heavy) swing to the porch stairs so I could have a sit in it. I was very happy with the result. Very comfy and it felt solid.
The arm rests were simple, but functional. I wasn't 100% thrilled with them, but they work and I haven't come up with a better option. If I ever do though, they're held in place by bolts so they're easily replaceable.
Step 6: Staining
This was, hands down, my least-favorite part of the entire process. Staining slats was really annoying. It might have worked better to stain them before assembly, but I made a lot of little adjustments to it during the slat installation and I ran a router with a round over bit over all the outside edges once it was assembled. I didn't think that staining it multiple would look right (or at least I didn't trust my ability to stain it multiple times and achieve the same color every time).
Even though doing it sucked, I was happy with the end result. I also hit it with several coats of spray on varnish which was a lot easier to deal with than the stain.
Step 7: The Finished Product, Installation Notes
And here you have the porch swing in all its glory.
The chain arrangement was taken from my research and it seems to work really well for keeping the swing upright while providing maximum support to the seat area. I'm happy with it, although it did make it a fair bit more complicated to hang the swing in the first place.
I also used 4 porch swing supports. Normally they're sold in pairs for use 2 to a swing, but I thought this worked better. They're rated at 250+lbs per support and they're put into the rafters in the porch ceiling so they're not going anywhere.
My estimate is that the swing can probably safely support about 700-800lbs. I've loaded it to 600lbs without any problems and really, it's plenty strong enough to handle 2-3 people of any normal-ish size. At this point it's also been in place and in use for a little over 4 years so I'm pretty confident about its sturdiness.
Oh, I did add some extra supports at the bottom. If you look closely you can see angle braces running along the bottom of the main supports. Strictly speaking they're not absolutely required, but after spending all that time building the thing I decided to err on the side of safety so I added those on before I put it up.
Step 8: Action Shots
Proof that the porch swing can actually hold people. First the low stress test with my smallest nieces and nephews, followed by the "real world" test, my father, sister-in-law, niece, and mom all sitting comfortably (neither of which was the 600lb test ;-)