Russ Herrell
Member

Hi, Russ,
Lowe's had what amounted to a plastic L shaped piece that I used for spacers. I ran the corrugated material perpendicular to the joists, so the spacers just attached to the joist. I just used a piece of string to set the slope and ran the slope about 1/4" per foot.

Good luck with your project.
-Josiah