I bought one of these canopies from HarborFreight: https://www.harborfreight.com/10-ft-x-20-ft-portable-car-canopy-63054.html. I'd like to anchor it down so wind doesn't move it. It has a circular plastic base plate with 4 holes per leg. Not super heavy duty.
Four of the 6 legs are on an old concrete slab in front of my detached garage (the other two are on dirt). I purchased some 1/4"diameter 2-3/4" long Tapcons (with the hex head of course). I drilled the hole longer than the Tapcon, cleaned it out well but the Tapcons keep breaking when installing them (I use a 1/4" impact driver). The head is fine but the actual bolts seem to break in half. I also have some 1-3/4" (also 1/4" diameter hex-head) Tapcons and these seem to go in without breaking.
Are the 1-3/4" long tapcons sufficient here or do I need the longer length? I bought the longer ones since it seemed like the long legs of the canopy would have a lot of torque on the shorter Tapcons. But it seems the concrete may be too hard for the longer bolts.
Are there different kinds of removable anchors that I should be considering? Someone suggested Red-Heads but all of the ones I've seen aren't removable. I need to be able to move this thing in the future.
NOTE: I realize this is a flimsy structure that won't hold up to strong winds no matter how it's anchored. The point is to not have it move with the kinds of light winds that are a regular occurrence where I live. I may replace the plastic bases with metal ones and I will use self-drilling screws to attach the legs to the bases more securely (they just slip into them right now).