Garden Arbor

We enclosed part of our backyard so my wife's dogs could run freely, but we needed a gate in the fence to access the rest of the yard. My wife had the great idea of combining a garden arbor with a gate, so I set to work trying to find a garden arbor that wasn't flimsy plastic, ugly, or expensive as hell.

Turns out that such a creature is purely mythological, so I decided that I needed to build my own. I browsed the web for arbor plans, and found many, but liked none. Well, actually there were several I liked, but they were very complex. Complexity isn't a problem in itself, but I had a deadline, so I wanted something simple.

I sat down with AutoDesk Fusion 360 ("Free for students, enthusiasts, hobbyists, and startups"), which I had never used before, and began making mistakes. That's how you learn, after all.

This isn't going to be a review of the software, except to say that it's rather different from the usual CAD paradigm. It wasn't hard to learn, though it did take several days before I really had a good idea of what I was doing.

Here is the result:

Construction Begins

A not-very quick trip to Lowes, and I had me a nice big pile of wood.

Four 4x4s, preserved and ground-contact rated, and four 2x8s, preserved but not ground-contact rated. In the background are two of the four trellises (trelli?) that will form the sides and gate, and a pack of 16 deck balusters. They're about 1½ inches square, and 3 feet long.

I set up a temporary workshop under the back porch, only a few steps away from where the arbor would be built. I hauled my bandsaw out there, only to have it disintegrate when I turned it on - the rubber tires upon which the blade runs flew to pieces. Being a strange little bandsaw that I had gotten at a garage sale, there was little chance of finding parts for it, so I guessed I needed a new one.

In the mean time, I needed a band saw, so I called my father to see if I could borrow his. "I have four of them," he said, "I'll give you one." So I ended up with a virtually new Craftsman 12" bandsaw, complete with stand, for nothing! Thanks Dad!

Step one is, as usual, the first thing you do, which turned out to be making a template to cut the arch sections. Euclid would be proud - since these were 60° sections, I was able to use an equilateral triangle to lay them out perfectly on a piece of 3/16" plywood.

I had thought I could fit four of these on each 8' 2x8, but I couldn't - I needed another 2 inches, or I could have gotten 2x10s or 2x12s instead. I made up for it by shortening the tangent sections of the end arches from 12" to 9", so I could fit all four of them (they nested nicely) and the last arch piece on a single 2x8. Then I cut them all out on the band saw.

Lots of bandsawing later, I assembled them into the complete arches. I clamped the ends to the table exactly the right distance apart (48 " on center) before screwing them all together with 3" wallboard screws.

Then it was simply a matter of cutting a step into the ends of the 4x4 posts, and attaching them to the ends of the arches.


We rented a power auger to dig holes in the ground, but I forgot to take pictures of that step. I screwed a section of plywood across the bottom of the completed arch, both to keep it in the right position relative to the sidewalk, and also to keep the posts exactly 48" on center. This would have worked pretty well, except that the sidewalk wasn't level, so the arch came out a bit crooked. More on that in a bit.

Once the complete arch was in the ground, we back-filled the holes with expanding foam rather than concrete - it was more expensive than concrete, but MUCH more convenient. Surprisingly, it holds pretty well.

Then it was time to make the gates. The gates are made out of garden trellises with the bottom pointy bits (the ones meant to be driven into the ground to hold it up) cut off. They were not too terribly expensive (something like $35 each), but seemed pretty sturdy and looked nice. They are 22" wide. The openings in the gates were big enough for the dogs to slip through, so I added some crossbars made from 3/16" steel rods. I drilled through the inside surface of the latch side of each gate, and through both the inner and outer surfaces of the hinge side, so the holes won't be visible (at least when the gate is closed).

To keep the rods from coming back out again, I drilled the two holes on the hinge side slightly offset, so the rod wouldn't go straight across to the hole on the opposite side. I'd then gently spring the rod to line it up with the hole on the other side, and tap it in the rest of the way. It would straighten out once the end was past the outer surface of the hinge side of the gate, and no longer line up with the hole. This kept it trapped. This is visible in the image below.

I had intended for these gates to swing both ways, but there wasn't quite enough space hinges that could do that. Instead I put them on the sides of the gate, so it can only swing inward. They're very simple - just L-hooks screwed into the posts, and an eye bolt on the gate. The one on the bottom has a spacer so that the eye-bolt can't loosen and turn sideways, jamming the hinge. I added a bracket above the top hinge to keep the gate from being lifted off the hinges (barrel hinges - remember the Pirates of the Caribbean?).

Now that I knew the trellises were going to work as gates - and that my wife would like them - I bought two more to use as the sides. If the trellises hadn't worked out as gates, they'd have been used as the sides instead. I simply put the second completed arch into place - again using the plywood crosspiece to position it so it would come out parallel to (i.e. just as crooked as) the first arch, and then screwed the trellises to the posts between them. Since it is on a hill, the second arch had to be shimmed up to the right elevation, so the plywood didn't sit directly on the sidewalk.

I added the pieces across the top, spacing them every 15°. I used the original template, with the middle and quarter points marked, to position them. I didn't add the outermost two yet - I want to first add the decorative trim at the point where the posts meet the arches. (You can really see how crooked it is in this picture.)

Before pouring the footers for the lower arch, I used a giant lever to pry the low footing of the upper arch out of the ground a few inches to level everything. (Interestingly, the hardened foam remained attached to the post, and pulled out of the ground. I then compacted the ground around it to lock it in place again.)


...and then I hurt my back. At the moment, the project is on hiatus until I recover (if I do ... long story). The arbor gate is useable as is - it keeps the dogs in while letting the humans pass, which I guess makes it a dog-filter? - but it's not quite done. Still remaining:

To be continued...



© 2016 W. E. Johns