Backyard entertainment, Phase 1 (part 1, framework)

This has been going on for a while, but I wanted to make sure it got done before posting, so I didn’t end up with a start without a finish.

Mason and I talked last year about setting up a treehouse. I had plans for an octagonal one, with the tree in the center, but I had neither the skill nor the equipment for tackling something like that. But as fall started, we were poking around the backyard (that got expanded about a year ago), and Mason looked at a trio of trees… arranged in a near-perfect equilateral triangle, about 12 feet (about 3.6m) on a side. “We could put it up here!” he said.

I remembered a smaller platform I set up for The Boy, when he was about 9. It was arranged similarly, in a triangle of trees. Definitely something within my skill and equipment sets, as both had improved in the past 20+ years. So that night, I sat down and started mathing it out—how many 12' 2x10 boards for the supports and joists, how many 5/4x6 decking planks—and made my grocery list.

The order was ready the next day, so we jumped in M.O. the B.B. to “pickup” the load. A few hundred pounds of lumber doesn’t even start to settle the suspension, but the support lumber did stick out somewhat past the lowered tailgate. I tied a safety flag to the end, and clattered home.

I got the first two boards up without much effort: put one 6" Timber-Lok screw through it and into the tree, lift up the other end, level it, then screw it in. You can see I put three screws in each end; if I’m reading the box correctly, that should support about 700 lbs (317kg). There’s two supports for each corner, so (assuming weight is evenly distributed) the platform should be good for about 4200 lbs (950kg) minus the weight of the platform itself. Over-engineered? Maybe. Mason and his friends are 8-10 feet off the ground. It needs to be safe.

The third, highest off the ground due to the slope of the yard, took some more effort. I finally tied a rope around it and used one of the other supports as a pulley. That actually worked better than expected, and I soon had it bolted in place.

Mason had to try it out, of course, unfinished as it was.

Now it was time to measure and cut the joists. I spaced them on roughly 2-foot (0.6m) centers, set the circular saw to cut the ends at the right angle, and used joist hangers (plus a Timber-Lok screw) to make sure it stayed in place. I got up all but the last (heaviest) one on Saturday, and Sunday brought rain. (Yes, this was something done over several weeks.)

With a lot of heave-ho’ing, some unsafe work practices (Charlie missed getting bonked with a falling 2x10 by inches), and many magic words, I finally got the last joist into the hangers and used a hammer to pound it down level with the support beams.

Yay, time to put down the decking! That comes in the next post.