Walls and Ceilings - Fire Stop Questions

I will be framing my basement, which has sewage pipes running along all the walls. Therfore I need to offset the walls out by about 6 inches.

I know I need firestops.

1)But for vertical firestops do I need to use a piece of wood to go from inside the studs to the foundation wall the full six inches? (Like Shown Below)
____________
|_||
| ||
| ||
| ||
| ||
| ||
|_||_______

2)Can I use plywood and how thick?
3)How do I get this plywood to stay up against the foundation wall?
4)And is the 18 inches a min or max. Can I go 10 inches from the floor above?

5)Second, for horizontal fire stops every 10 feet, do I use the same techniques? One big piece of plywood the hieght of the room and long enough to get to the foundation.
6)Can I make notches for the sewage pipe?

Thanks,

Noel

To be honest, I don't understand the firestop issue. But I think that I would use 2X6s instead of 2X4s for the framing. Your firestops would be easier to install (use 2X6) and the wall would be uniformly spaced from the outside wall. Also, the 2X6s could be attached at intervals directly to the outside walls. The price difference is probably worthwhile, considering the problems that it will eliminate. I'd at least price it out and evaluate the option.

Firestopping materials stop smoke, fumes, gases, and fire from spreading from room to room and floor to floor. Firestopping should be done in strict accordance with local building codes and the National Fire Protection Assoc. guidelines. Material should be installed according to manufacturer's specifications by a qualified installer.

Go to www.bdacorp.com/firestopping/howto.htm for helpful info.