I bought this material at ww that I thought was waterproof and made a tarp. It was ok in a shower but leaked in a hard rain. I treated it with thompsons waterseal but it still seeped in hard sustained rain. So, I got some silicone caulking and mineral spirits and mixed them up kinda thin and painted it on with a brush. It has dried more than 24 hours. It is forcast to start raining in about an hour. The hammock is under the tarp and ready to go. I may have to walk out in the rain but I'll report back on how it works. I also have my new insultex diy underquilt with vapor barrier bottom on. It is only sposed to get down to 52 so it won't be a good test for the insultex. My poncho liner doubled is good to 48. I think the double layer insultex should be good to 40 and the combination good to 30. Gotta wait awhile to test those temps.