I plan to attach plywood sheets to my basement ceiling (2x10 joists,
16" OC). The application is an extension of a climbing wall (I will be hanging climbing ropes and holds from the plywood).Every inch (of height) counts, so I want to attach directly to the joists rather than use furring strips. The structure is sound but the lower surface of the joists aren't all at the same height...maybe up to 3/8" difference across the area in question.
I can't use the traditional shim technique, so I was considering building up 1.5" wide strips of material (felt paper?) along the underside of "high" joists to bring them down to the level of the others.
Aside from being a bit strange, is this a really bad idea? I'm thinking that felt paper will also help to reduce sound transmission to upper floors.