Got some random questions here:

Any tips or tricks on using asphalt shingles to help with leveling? I'm assuming there is going to be a void between where the plank is sitting on the subfloor to where the shingle starts. Does this void need to be filled with something?

Can you use hardwood flooring on stairs? If so, is there a how-to on this board?

I live in a split level ranch. The hardwood floor is going on the top floor. Does that mean I can use rosin paper instead of the 15 pound felt since I won't have any moisture issues? However, could I use the felt as an aid in leveling by using multiple layers?

Thanks for any input.
Josh

found the info on flooring on steps on the homepage so disregard that question!

I use 15 or 30 lb. asphalt felt paper to transition between shingles and subfloor. Simply fold it and layer it as needed. Works great. A hammer tacker holds everything in place.

You can use red rosin but why? It's not cheaper. Already answered second part of this question, YES, you can.

Good Luck.