In 2004 or was it 2003 when our cheap shit pop-up shade structure was whirled instantly into a ball of lousy plastic and shards of broken aluminum, it occurred to me that we needed something slightly better.
Where to find such a thing? We sought out help using the intertubes whereby we found a previous burners' experience to swipe from. Alas, I kept lousy notes and do not have this person(s) name or intertube earl.
2007 was the third time we used this thing, and it's held up pretty well, with one major weak point described below. We never lost it though, it survived 70mph blasts on a couple of occasions. I wish I could give credit to the originator of this thing, oh well.
The thing is made out of a bunch (you count 'em) of 10-foot one-inch white PVC pipe, with one length of 1-1/2" chopped into foot long pieces for use as couplers. There is actual cleverness in the structure. The parts list as best I can recall is:
The pictures tell the story. (Or if it doesn't, tough luck, that's all you get.) Here's the high points, if they aren't obvious from the photos. The rebar locates the hoops, and does a fair, but not adequate, job of holding the structure down to the earth. Anywhere but the playa they would be more than enough!
The bicycle-tube rubber bands and the slip couplers are the major tricks. The slip couplers hold absolutely, and have never moved around. There's no need for pins, through-bolts, etc. Friction is plenty, yes, even on the playa. In fact, the major reason for failure in PVC structures are weak points caused by stress at drilled holes and metal pins! With the slip couplers, stress is distributed evenly over much area.
The rubber bands are the second secret; they tighten under stress! The also distribute load, and allow the structure to flex such that load is distributed over the skin, the hoops and other rubber bands. Rigid bolts and pins concentrate force on a small area.
The major problem with a quonset hut, that a dome solves, is when wind comes at a 45-degree or so angle to the hut; it applies side and upward load on the skin from the inside. This lifts the hoops off the rebar and the whole thing loses strength at that point. The hut is fine when the wind is broadside to the skin, or end-on where the wind passes through (obviously). Broadside wind just makes it hunker down and even increases the grip on the rebar that side. Domes are all "broadside" so they don't generally lift off unless you let the wind inside (oops).
The solution to the most of the lifting problem is the trucker tiedowns. They simply apply rubber-band type force to the skin edges, near the openings, that increase in downward force as the wind lifts. There is still a fundamental problem with the 45-degree wind lift, which a rope off the end, boy-scout-tent-style, helps solve. It's all a kludge, admittedly, but it does work.
A possible solution is a PVC dome-ish structure, eg. a quonset hut that's all sides using this general technique, which is otherwise quite sound. I will likely try this, but the quonset hut is a great daytime hangout!
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