What woodworking joints can I use to join crown molding trim?

When installing crown molding trim, there are 4 possible joints that you will encounter. Each joint serves a particular purpose and occurs at certain spots when decorating the upper corners of a room. The 4 joint types are coped, butt, miter and scarf.

  • Butt joints are uncut, 90-degree ends that fit flush against an adjacent wall or surface
  • Coped joints work in conjunction with butt joints. With this type of joint, one piece of molding is intricately cut to match the profile of the adjacent piece, thereby making a corner joint that fits like puzzle pieces
  • Miter joints require a 45-degree angle cut on adjacent corner pieces. The cuts are made in opposite directions but form a 90-degree (or thereabouts) angle on an outside edge
  • Scarf joints are used to splice lengths of trim along a single wall