Sukkot Project Management

It's a busy season for the Jewish people right now: it's sukkah-building season! Sukkah styles vary dramatically, and that includes me building several iterations with the same pile of lumber for more than a decade.

As I write this, we're in the "10 Days of Awe" between Rosh Hashanah (the Jewish New Year) and Yom Kippur (the day of atonement). Only four days after Yom Kippur is the week-long holiday of Sukkot, which requires people to "dwell" in a sukkah (temporary structure with specific construction rules) during the holiday to commemorate the time that the Jewish people spent wandering in the wilderness between the Exodus from Egypt and their arrival in Israel.

I didn't grow up with the sukkah tradition, but adopted it during and after college: at least one meal in someone's sukkah, and often helping build one. Before I moved into my first house, I observed how other people and organizations had designed their sukkahs and came up with how I wanted to design mine. My priorities included:

• Solid walls (plywood rather than cloth) because I'd experienced some cold nights and blown-out candles in others' cloth-walled sukkahs
• Assembly using 3/8" bolts and nuts rather than screws or other fasteners to maximize reusability
• A wrench had to be able to spin 360 degrees when tightening bolts to ease assembly (this ended up being misguided, more on that later)
• 8' x 12' footprint (3 sheets x 2 sheets of 4'x8' plywood) as a good overall size
• As much as possible the sukkah should be a one-person build

Overall theme

I've gone through at least three generations of sukkah design since I started, but I've used the same lumber and hardware throughout. The roof (which by definition of a sukkah isn't structural) changed, and I had to buy a few more nuts, bolts, and washers on occasion, but the flexibility of the underlying materials is amazing. In the Right to Repair movement, a mantra is "screws not glue": build things in a way that allows them to be disassembled and repaired. I've avoided cutting anything to size where possible and thus enjoyed flexibility as my understanding and needs have evolved.

My sukkah has become a passion project for me, like some other events and products.

Generation 1 - Crunch!

My first design took the most inspiration from my synagogue's sukkah: 4' x 8' sheets of plywood permanently attached to 1" x 1" lumber for strength. The synagogue's sukkah put a 1x1 on all four sides of the 4x8 sheet to form a pre-assembled panel, and the panels bolted to each other through the adjacent vertical 1x1s; the bolt-holes were parallel to the plywood. The downside of this design was that people could only tighten the bolts a half-turn at a time before the wrench hit the plywood, which was a pain.

My "brilliant" (not really) innovation was to run the bolts perpendicular to the plywood (from inside to outside), which meant that a wrench could turn full circles. the 2x2 on the interior was permanently attached to a 4x8 sheet, and the bolt ran through both to attach to a 1x3 vertical beam on the outside which was nailed and glued to the adjacent 4x8 sheet of plywood. This had two flaws:

1. To tighten the bolts, someone had to be on the inside and the outside and work as a team to prevent the nut/bolt from spinning, and
2. The 1x3's nail/glue attachment to its 4x8 sheet was a structural weak point which tore off under stress

Several friends helped me build my generation 1 sukkah, which especially during the first build was extremely helpful as unexpected issues came up. A following year I called one of my friends from my ladder at the exact moment I realized that a one-person build wasn't sustainable with that design. I lucked out: he was able to come over quickly.

My first backyard included a long open area where wind could build up and caught the long end of the sukkah. I had not installed any horizontal stiffeners in the walls, trusting the plywood and the ceiling's cross-bracing to keep everything square. This was a mistake: the middle of the long wall dished in and the sukkah partially collapsed on windy nights (never when anyone was inside).

Generation 1 no longer safe for use:  note the sukkah was pushed towards the house and forced the house-side wall off vertical

Generation 2 - Triangles and tolerances

For one or two years, I reinforced some elements of the generation 1 sukkah, but eventually I gave up and redesigned. I bought a pre-made roof (saving a lot of effort getting tree trimmings), which also freed up some loose 1" x 2" lumber I had used as the roof before. I went wild with bracing: every 4x8 panel would be backed with a pair of 8' 1x2s in an "X" shape which would tie to each vertical 2x2. In addition, I gave up on the perfect 8' x 12' footprint to have the 4x8 panels now overlap over the bolts: the joints between 4x8s were now overlaps rather than adjacent.

2.0 - Tolerance failure

The first time I built the sukkah in this fashion, I found that the various match-drilling and "close enough" measurements I'd done were insufficient when every bolt was now carrying the tolerance stack-up the bolt-hole locations in 5 pieces of wood: the two 4x8s being joined, the 2x2, and the two diagonal 1x2s. I also drilled out and installed bolts at the center of each "X" to keep all of those joints square, which meant that the excess length of the bolts now interfered with the middle of the 4x8 sheets. Generation 2.0 ended with my decision that the skeleton sufficiently defined the walls and I chose to not install most of the 4x8s that year.

Generation 2.0 did easily accommodate a hammock for napping

2.1 - Now with solid walls

The following year I took the momentous step of drilling holes in the center of each plywood sheet to accommodate the bolts in the center of the "X". Tolerance stack-up was even more painful, but the walls were complete. The main downside of this sukkah were the sheer number of connections, which meant that assembly took longer than generation 1. Building the skeleton first allowed me to install a nut on each bolt for the skeleton, then install the plywood on top with another bolt. This solved the inside/outside issue at the cost of requiring more hardware and spacing the plywood away from the skeleton so that the corners now had gaps where the wind could come in.

Generation 2.1

Generation 3 - The latest and greatest

My current setup is a hybrid of what came before. It adopts the overlapped 4x8s of generation 2 and some structural reinforcement but a lot of the aesthetic of generation 1. Rather than criss-crossed 1x2s, generation 3 relies on the 4x8s to keep the vertical beams vertical. Instead, top-and-bottom 1x2s run horizontally to add structural stiffness and partially solve the inside-outside assembly issue. The 12' wall horizontal beams are paired overlapping 1x2s with four bolts permanently installed which match the attachment points for the three 4x8 sheets. Because those bolts are already installed and tightened, I can install nuts on them from the outside without the bolt spinning on the inside. I can also do more pre-assembly on the ground.

I've refined the design to incorporate solid spacers at the corner (more 1x2s) to prevent air gaps, and the overall design is very stiff and wind-resistant. It takes 3-4 hours for me to put up (including taking it out of the garage). Over time, some bolt-holes have had to be re-drilled and some of the difficulty in assembly is identifying the right hole for the bolt, but continuing labeling helps solve that issue.

Mostly-assembled generation 3 sukkah this year

Conclusions

As noted above, the combination of plywood, dimensional lumber, and bolts/nuts/washers is extremely flexible. I did not expect to iterate so much on my original design, but I should have. I've stopped using some pieces of my initial design as they've become redundant, and I regret some of the unused holes in various bits of lumber, but for 10+ years of service (certainly since 2015, I think reality was 1-2 years before that) and 3+ generations of design, I really can't complain.