Instead of drywall screws -- I use 4" - 7" lag bolts -- the wetter the underlying mud, the longer I need. Fender washers help keep the grommets from tearing out of the tarp plastic. They bolts have 7/16ths head -- I use a socket in the drill chuck to install/remove. Have a spare battery or charger handy, too.
Screw down EVERY grommet hole. If you skip one -- that's the one the wind will get under and start tearing the others loose, resulting in you having to chase down your tarp as it heads towards SLC. Also place heavy stuff on the edges at night, and probably something in the center, too, helping reduce the "bubble" that'll form when the wind gets under there anyway.
