I have an uninsulated garage with pressure-treated sill against a concrete slab, which I now want to insulate. The sill is directly against the concrete slab with a simple plastic film in between. I don't want to trap moisture or risk the pressure-treated wood starting to emit odor; I got advice from an inspector to replace the sills with regular wood and lay sill seal underneath. The question is how to support the walls at the ceiling during the procedure, and how to splice the sill seal? I assume there will be many seams during the process. Grateful for tips, happy Easter!
