1. Is felt paper used for flooring and roofing felt paper the same thing?

2. Is there a proper side of the felt paper that should be face up?

Same thing. It will lay flatter without puckering if you flip it over with the pre-marked lines facing down. Comes in 15 lb. 432 sq.ft and 30 lb. 216 sq.ft rolls. 15lb. is what most of us use.

Thanx Jerry.

A few people questioned the use of roofing felt paper because they though it would have a smell and I couldnt say this is what should be used.

Most people use construction paper or wax paper around here and I refuse to use construction paper and the wax paper seems so cheap.

Ashalt felt will not smell UNLESS there is radiant heat under it. Then use red rosin.

I might add that I've switched to a membrane impregnated underlayment

Here it is:

http://www.fortifiber.com/pdf/data_shee ... abar_b.pdf

I get it for free so I'm not sure it's cost effective for most

We use the Aquabar as well. We pay about $12 per 500ft. roll. Easier to handle (not as heavy to carry etc.) than the felt and more reliable than the rosin. Same price (here anyway) as the rosin as well. Makes a decent floor cover for some protection for short periods of time.