will roofing tar paper work as underlament for a wood floor?

Answer 1

Tar paper works as an underlayment. There’s better materials out there but tar paper works fine as an inexpensive underlayment in a dry environment 

Answer 2

since it will be unprotected from the underside, and thus exposed to a lot of damp, the answer is no.  use proper plastic sheeting to repel damp -- and promptly clean up any water spills on the flooring [unless the flooring is impervious to water -- sheet vinyl, for example].  -- grampa

Answer 3

Work in what way? What do you want it to do?