In this video, Ask This Old House general contractor Tom Silva shares his tips and techniques for installing decorative crown molding.
1. Take a short scrap piece of crown molding and hold it against the wall and ceiling in a corner of the room. Draw a pencil line along the bottom edge of the molding and onto the wall. Repeat to mark all remaining inside and outside room corners.
2. Connect the pencil lines by snapping a white chalk line onto the walls around the room.
3. Mark the locations of the studs onto the walls.
4. Hold the first length of crown molding in place against the wall and ceiling and tight into the room corner.
5. Mark the wall-stud location near the middle of the wall onto the molding.
6. Place the molding upside down in a compound miter saw. Hold the molding flat against both the saw's vertical fence and horizontal table.
7. Adjust the saw's miter angle to 45 degrees and cut a scarf joint into the molding.
8. Hold the crown molding in place with its square-cut end tight in the room corner and its bottom edge on the white chalk line.
9. Nail the crown molding to the wall studs and ceiling with a pneumatic finishing nailer and 2-inch nails.
10. Hold the second length of molding in place against the wall and ceiling, making sure it extends past the scarf joint on the previously installed crown molding.
11. Mark where the second crown molding overlaps the scarf joint.
12. Cut a mating scarf joint into the second length of crown molding.
13. Apply carpenter's glue to the scarf joint, then hold the second length of crown molding in place. Be sure the scarf joint fits tightly together, then nail the molding to the wall and ceiling.
14. Miter-cut a length of crown molding for the next wall. Then back-cut the miter joint with a coping saw to create a coped joint.
15. Apply a bead of white acrylic-latex caulk to the coped cut. Hold the molding in place with the coped end pushed tight against the crown molding previously installed on the perpendicular wall. Nail the molding to the wall and ceiling.
16. Repeat the previous steps to nail crown molding to the remaining walls. Be sure to cut scarf joints along the walls, and coped joints at inside corners.
17. If the room has any outside corners, cut a 45-degree miter joint onto each end of the mating lengths of molding. Glue and nail together the miter joints.
18. If installing molding to a brick or concrete-block wall, apply construction adhesive along the back, bottom edge of the molding and nail the top edge to the ceiling.
19. Caulk along the top and bottom edges of the crown molding, then fill all nail holes with wood putty.
20. Paint the crown molding with high-gloss latex paint.