Walls and Ceilings - Tile Plank Ceiling Backer

I'm putting an Armstrong plank style tile ceiling in my new bathroom. The tiles will run perpendicular to the ceiling joists, but I read in the tile installation instructions that I can't attach them directly to the joists. Furring strips are also out of the question since they too would have to run perpendicular to the joists, leaving the tiles parallel.

At this point I'm thinking of just putting drywall up there and attaching the tiles to the drywall. Would you recommend my doing that, or is there another solution that I don't see?

Thanks...

Brian

What does the manufacturer recommend?

They recommend either their track system (not an option) or furring strips. They do say that these can be attached to drywall. As I said, I'll do that unless somebody gives me a better idea...

Two layers of furring strips, each perpendicular to the other? That would restore the right orientation for the planking. Just thinking out loud trying to avoid installing sheetrock.