crabshell wrote:
Long story short, I need to attach baseboard molding to a sheetrock wall.
The problem: instead of having a 2x4 behind the drywall to nail it into,
there's concrete. So we're talking 1/2 inch drywall butted up against
solid concrete. I'd rather not use glue/silicone because removing the
baseboards some day would in theory destroy the wall too. Any ideas?

Why would you have to remove the baseboards? In any event repairing
drywall is not big deal. If you're dead set on finding an
alternative, you could use an old method for attaching molding to
brick walls. Drill holes, insert wood dowel plugs, and nail into the
dowels.

R