I have a typical floorless shelter/tent, and in a few months I will need to use it in a very wet place. I expect rain puddles, and there is only so much that you can do with tent location when the ground is basically flat. Obviously, I need to construct a bathtub floor of sorts to insert in there, and it will be about 6.5 feet by 2.5 feet. The upturned edge will need to be at least a half inch to keep water out.
I made one out of coated nylon, and it turned out several ounces too heavy. I mean, it is too heavy when the bathtub floor weighs more than the entire top of the shelter/tent.
Now I have some yardage of spinnaker fabric and some Momentum fabric. Gut instinct tells me that the spinnaker fabric would be better there. Alternatively, I have a painter's dust tarp of 0.7 mil plastic. It's pretty light, waterproof, not very durable, but I can't upturn the edge or sew it.
Weight is a factor at play here, but durability is not. This only needs to last through the puddles for six nights or so. Any suggestions? Meanwhile, I will get the sewing machine warmed up.