Is Tar paper safe for indoor use?

Answer:
Yes, depending on what you use it for. 15 lb. felt (standard tar paper) is what is used as a vapor barrier under sand and finish hardwood floors. It can also be used as a moisture barrier behind HardiBacker or Durock on shower walls that are tiled.
First answer by JPC2. Last edit by JPC2. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 1 [recommend question].