I now have the tyvek so it is ready to test. First, I tested to see how waterproof it is. I put a sheet of the tyvek over a bowl and secured it with an elastic band. I then poured water into a dip in the tyvek. I kept the water on the tyvek overnight then removed the sheet. I found that the bowl was completely dry, no water had seeped through the tyvek, therefore it is waterproof.