I'm putting beadboard halfway up the wall in a room, two walls of which are masonry. One of the masonry walls is an exterior wall that is double-thick brick (almost 16" deep!). The other is an interior wall (between townhouses) that is concrete block.

What is the best way to beadboard these surfaces? I came up with
  1. Fir, then beadboard on firring strips
  2. Drywall, then beadboard
  3. Fir, then drywall, then beadboard
  4. Some combination of the above + some sort of insulation

Drywall directly on the masonry seems like a moisture problem waiting to happen. Fir + beadboard seems like an insulation problem, although I have to say it's not a big concern given that the wall area in question is small (about 6x4) and the brick is really thick. Fir + drywall + beadboard might be an obvious good solution, but would end up being too thick unless I use really thin firring strips and/or really thin drywall.

If it matters, the beadboard is tongue & groove hardwood.

I'd be glad for any ideas or thoughts.