Originally Posted by Cyclebum

Thanks for all the responses.

Apparently, the only real advantage a manufacturered ground cloth offers over DIY is with free standing rain flys that use the grommets as pole anchors. I guess that's why they are rarely included in the price of the tent.

I use blue or brown tarp material, cut to size. Guess I'll stick with that. Or maybe just slather the floor with silicon and not bother with a ground cloth any more.