Some Gortex fabric is available locally. Lookin at it, it does not look very substantial as far as being water-proof. It is from a U.S. manufacturer, and is unquestionably the real thing.
Is Gortex used as a single outer layer, or, is there another barrier layer which is required underneath the outer Gortex to make it completely water-proof?
It's weight seems like it would be a great tarp material.