How to Install Three-Piece Crown Molding

On the fascia, mark a line where the lower edge of the upper molding should fall. Position the first run of molding along this line, and butt its square-cut end against the corner. Drive 2-inch nails through the molding and into the fascia, then drive 2-inch nails through the molding and into the joists or backing blocks. Don’t add nails within the last few feet of the coped end in case adjustments are needed when the adjoining run is installed.

See a typical sketch for laying out crown molding in a room.