How do I shape crown molding to fit a ceiling that is not straight?
Andy Rae: No ceiling is perfectly flat. When the ceiling gets really lumpy or bumpy, I use a short block plane to trim the top edge of the molding until it fits a bit closer. However, don’t expect miracles here. Gaps three-sixteenths of an inch wide or more are not uncommon with well-executed crown molding. Your best friend is caulk, which comes in paintable varieties if you’re going to paint, and in tans, browns and blacks if you’re not. Once you’ve nailed the crown in place, dispense an even bead of caulk into your gaps with a caulk gun, and then wipe it smooth and even with the tip of your finger. Keep a rag moistened with the caulk’s solvent on hand, to help smooth the joint and to keep your finger clean for each wipe.
Kevin Hancock: Hold the piece of crown parallel to the ceiling and use a duck bill scribe to draw a line parallel to the contour of the ceiling, then cut to the line.