Hi guys. Thx for the message boards.
My quest is to install solid treads on my stairs that were preveiously carpeted. I am installing over the plywood the carpet was on. Each plywood tread slopes from riser to nose an 1/8 of an inch. Should I level that out with asphalt shingles or is there a reason they slope?
BTW it does not rain inside my home so I don't think its for runoff.

I had one "master carpenter" who's rough stairs he built for me call that off level slope "comfort". An 1/8" slope over an 11.5" run is approx. a 1 degree slope. That's not much but if it bothers you, you could "level" it if you wish.

Personal prefence.
I like flat, but others like slope. Then others like Ice Cream with hot apple pie...........
1/8" is not much of a noticeable slope to the eye. I don't think I would take the time to try and make that flat.. but I'm old and lazy.