I need to replace the sill plate by the side door of a 1 car detatched garage. Can this be done by simply cutting out the bad area and placing a new treated board in its place? Is this more involved than that? I the bad area is around the door, but I plan on cutting back about 4 feet to be sure.
Yes, you can cut it out and replace it. If it is a large area, do a temporary shore-up of the ceiling joists. Either way, cut the nails with a recipricating saw and dig the pieces out and replace...Just make sure that you find what the actual moisture problem is and fix it first.