Tar paper under wood floor?

Q: I have to install wide pine flooring on a remodeling job. The original pine strip flooring was laid over tar paper. Why? Should I use tar paper under the new floor?

A: Charles Peterson, owner of Connecticut Premier Hardwoods, replies: Asphalt-saturated felt paper is used for two reasons: It’s a moisture retarder, and it helps to diminish noise caused by wood-to-wood contact. I recommend using it. (Rosin paper would cut the noise, but not the moisture.) First, though, check the flooring manufacturer’s instructions. Some recommend using a bead of urethane glue every 10 in. to 12 in. under the planks, which would make it impossible to use the felt paper. The glue won’t do much to stop moisture, but it will stop squeaks. If moisture migration is a concern, call the manufacturer; they may tell you to seal the backs of the planks.