I just bought a Trimline tent and made homemade PVC weights that are 40+ lbs each. Yesterday I practiced setting up the tent for the first time and had each leg weighted. I set up on my deck (fortunately only 4" off the ground on the side with no railing), and multiple times the tent actually blew off the deck at one corner! It probably would've blown off on the corner as well, except the hot tub stopped it. Ack!
I'm freaking out that something is not right with my setup. It wasn't that windy when I was assembling the top, so I didn't have the top vents open (the wind picked up later). I'm hoping opening those is all it takes to fix the problem, but this is scary since the tent was such a huge investment and I don't want it blowing away at shows with all my artwork.
I live in windy Breckenridge, CO, and the booth front was facing west when I set up. All my festivals this summer are in other mountain towns like Breck and who knows what direction I'll be facing.
Any thoughts on troubleshooting this?
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I clamp my weights to the base of the legs and have them sitting on the top of the foot plate. I've used this method with my Trimline and with my pop-up tent and both have withstood some very strong storms. I also put 1" thick rubber pads under the leg plates when on a hard surface. Each step adds up to increase the tents stability.
I use sta bars on both tents and they are invaluable also
I have a Trimline tent, use 45# sandbags (the nice looking black canvas bags made by EZ-Up), and I also do shows in the summer in the Colorado Rockies. I have been in VERY windy conditions and have had no issues whatsoever. Here are a few observations.
1. The surface of your deck is much slipperier than either pavement or grass, especially grass. Your tent is far less likely to move sideways when on those surfaces. Friction becomes your friend! Your deck boards were working against you on this test.
2. Weights are more effective at holding a tent in one spot when they are attached at the bottom of the frame. This is basic vector physics. If a weight is only attached at the top, as you have shown, then the wind can push the big white box sideways a bit while the weight is still being primarily pulled down by gravity. If the wind is strong enough, it will eventually drag the weights with it. This is even more of a possibility when the weights are hung so that they are suspended above the ground, meaning there isn't even a bit of friction between the ground and the weight! Remember, friction is your friend! I attach my sandbag at the top, but I also wind the webbing of the strap around each leg so that the weight is firmly attached near the bottom and there is no movement of the tent frame away from its weight.
When it is particularly windy at show, I will place each bag on the leeward side of its leg, if at all possible, to act even more as a kind of "door stop" for the leg. The only time I had my tent move was in Duluth, MN, when we had steady 25 mph winds all day with regular gusts of 45 to 50 mph. I know these numbers to be true since there is an airport one mile from the show site and I looked up the data for that day. My tent moved sideways 5 inches. Of course, some of the wall zippers never worked well after that....
Thanks, Jan! Luke from Flourish agreed with everything you said.
The weights can not be on the ground, they have to be above the ground. When they sit on the ground, you have less weight on the tent leg itself. An easy way to prove this to yourself is to set the leg on top of a bathroom scale. Check the scale weight with the weight suspended a few inches off the ground versus sitting on the ground as you have it right now. It'll open your eyes a bit to see the difference. The other issue is the surface the tent is sitting on. If it's slick concrete, it'll be almost like ice when the wind kicks up. Glue some tacky rubber to the bottoms of the feet to improve the grip. After that you should be okay. The most important thing is to get the weights off the ground.
Weights above the ground: yes and no, I think. If the weights are firmly attached to the leg, then the weight of the weight is added to the weight of the tent, PLUS, there is the benefit of additional friction on the ground. With my method (see my comment below), then the weight essentially becomes a very large foot on the tent. If the weight is just attached at one point at the top of the frame, as shown, and then suspended above the ground, it can still sway around and provides no additional friction benefit.
The weights should be secured regardless to avoid swaying under heavy wind. Duct-taped to the leg or zip-tied works either way. The weight adds directly to the leg pressure as long as it is on-axis with the leg. Get it further away from the leg and the effective weight redistributes to the rest of the frame. Part of why the weight in the air, but secured to the leg for safety, works is that the weight bearing on the foot pad increases. That improves the static friction and makes it harder for the wind to break the foot loose from the pavement. As I mentioned earlier, attaching either a tacky rubber foot or a piece of carpeting improves that friction. Spreading out the effective area of the foot with a weight bag on the ground is a trade-off depending on the 'grip' of the weight bag, but the hard surface of a PVC weight has a very low coefficient of friction and is worthless when sagging on the ground. I've seen tents with heavy weights like that walk several feet under heavy winds. BTW, when that happens and the tent bumps into a curb, the legs start to fold under unless they have Sta-bars. I use 50 pound bags of pea gravel when on pavement, and will use large dog stakes with ratcheting tie-downs when on grass. I far prefer the dog stakes. I figure if I have to use a long handled hammer as a lever to torque in those dog stakes, that tent is going nowhere.
The weight was off the ground until the tent blew off the deck, then the weight was touching the deck! Good idea with the rubber.
I'm sure there is someone on this site who can help you out ... I do think those weights should be on the outside of the tent, if that is any help.
In the meantime, did you "search" for weights on this site? There are loads of discussions and images that should be helpful to you.
Your weights look like ours! :D I am not sure what to tell you except try opening the vents if your canopy is still set up.