The good thing about Tyvek: waterproof, lets water vapor through and is (relatively) tough.
The bad: tends to be heavy and bulky to carry.
I have a bunch in my basement and wondered what to do with it. I was thinking of a poncho/ground cloth. My hesitation with the ground cloth is that the ground water vapor might come through, and defeat the purpose. Maybe a poncho, but I think an actual poncho, even an inexpensive one, would be less bulky and lighter and just as effective.
I will also be interested to see ideas for use.
I don't know anyone who has used it other than for wrapping a house under construction and as a tough envelope for shipping things.
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"Better is the enemy of good enough."