Hi Guy's I am a new poster but have based my philosophy on hiking on the knowledge I learn here. I am currently using a Guidegear 9'x9' tarp over a military pup tent mosquito net in an A-Frame shape. I use a Tyvek ground cloth and have been having a problem with water pooling underneath it, I pick high spots to pitch but water still seems to run in from many little arteries from around the edges. Has anyone been able to get Tyvek to stay in a tub shape? Or have another solution.