Hi, Suge -- At Kennedy Meadows, we got rid of our Tyvek groundcloth and hiked the rest of the PCT without one. Our Tarptent has a silnylon floor. It's not showing any signs of wear. So, I think silnylon is pretty durable if you are reasonably careful and that you could use it as a groundcloth. French Fry (AKA Kimber) PCT '03