The physics of canopy weights

I knew I’d been dodging a bullet with my crappy lightweight canopy at craft fairs, but today my luck ran out when a violent storm hit. No damage to canopy, inventory, or me, but a scary experience.

So I’ve just ordered a REAL canopy. I’ve been observing other vendors’ canopy weight systems, and I’m wondering which is better.

Most vendors I saw were using weights made from a 2-foot (ish) length of 3" PVC pipe filled with concrete, into which had been sunk an eye-bolt.

Some people used the weights this way: The weight was on on the ground, and a rope went from the eye bolt in the weight to a loop in the canopy. Some sort of tightening device was used to pull the rope tight. Bungees were then used to secure the weight to the weight to the canopy leg (I think primarily to keep people from tripping over them.)

The other method I saw was to hang the weights on the canopy frame near the tops of the legs.

From a physics standpoint, would one method provide more stability than the other?

Let me tell you about my canopy weights.

Mr. S took four half-cinder blocks, filled each one with concrete, and sank two bolts into the concrete before it set. The bolts fit around the legs of the canopy (and also rest on the little “lip” at the bottom), and then we put a small plate with two holes across the bolts, attach it with two wingnuts, and hey presto.

Extremely compact, inconspicuous, easy to carry and transport, easy to install. I don’t know why people mess with those other things.

Perhaps unfortunately, almost all of my shows are on grass, so I hardly get to use my nifty little weights (stakes instead). I don’t even know where they are right now.

Is your REAL canopy an EZ-Up? Worth the money. I also sprung for the side panels with Velcro. If the weather is iffy, I attach them at the top only and roll them up under the cap. If the rain starts, just roll them down WHOOSH and you’re set. I’ll also “flap them out” the back with bungees and stakes if the sun is an issue and I have the room – keeps the sun off but you still get airflow. They also help with security if you want to limit access from the back or sides. And they’re white like the canopy, so no color issues with your product, and they just look more professional than a bunch of bungeed tarps. (Although in the last year or so I started hanging panee velvet drops on my back walls to match my table covers.)

If the weights aren’t heavy enough for the wind load on the canopy, the higher the weight is the higher the center of gravity is, and the likelihood of the canopy blowing over increases.

I used to do weekend long SCA renfaires with my brother, we had one of those 12’ x 20’ knock-down garages with a custom made roof. On ground we used spiral tie-out stakes, two in each corner. They don’t like hard dry soil or sand, water helps with that. Pouring water on them after they’re in helps “lock” em in place, but you don’t want to make mud!
The tie-outs kept the beast on the ground in 30+ mph winds, folks with stakes were praying, folks with EZ-Ups were cursing.

The other option (if your not doing one day events and you’re handy) is a bulb auger and plywood disks. Make the disks with a hole saw, thread rope that will rot through the center hole. Drill your ground holes, drop the disks in, back fill and compact the fill (water helps with that too). At the end of the event just cut the rope off at ground level. More work than the tie-outs but the auger can put your anchors in twice as deep.

Neither of these options like rocky soil, hit a rock, move the booth a little.

Fortunately we never had a blow-over (did get to see a number of EZ-Up twisted into pretzels and/or have their tops blown off) or had to set-up on solid surfaces. If we had to the plan was to use 5 or 7 gallon “Spackle” type buckets (with lids or they become wet ashtrays :mad: ) or 5 gallon “jerry cans” etc, preferably black, and assuming that we could get water on/near site. One in each corner, with a second set ready if the weather warranted it. You could make water weights with the black not-pvc pipe and the right fittings.

Two bonuses with the water plan, you don’t have to haul all that weight with your vehicle and you’ve got 40+ gallons of hot (black containers!) water for cleaning up or showers if your overnighting it.

CMC +fnord!
BTW those tie-outs will go through the stake holes in the EZ-Up’s legs.

Scarlett67, yes, I bought an EZ-Up with sidewalls! I hope like hell it gets here before my show next weekend.

CMC, thanks for the explanation about weight placement and center of gravity. Alas, the rules for just about every outdoor show I do specifically state that NOTHING can be driven into the ground. :frowning: I’ve thought about the water weight option, but I do shows by myself, which makes that option more complicated than it’s worth for me.