The camo cloth on my blind is about 10 mil if I remember. I spray it down heavy with 3 M scotch guard before I take it out to set up. I suppose if you wanted you could put a tarp or plastic on the frame first then use the cloth to holt it from rattling. I see no need my self. Slope of the roof and the scotch guard keeps the inside dry but we do not experience days and days of rain here during deer season mostly we get snow.
No grommets in it either their are tie strings/cord to hold the rolled up windows open and tied down tite shut to. There is cord sewn in at the base to hold it in place, I used 10 inch pole barn spikes for that.
Brush it in a little if you have some in the area but if set up ahead of time the deer get used to it.
I've had tracks where it almost appeared they were looking in the windows before.

You will be surprised how much nicer it is setting out of the wind also how much warmer it will get inside when the sun shines on the dark cloth.

Al