To install wall moulding, measure the walls to assess the amount of moulding needed, and mark the wall studs to see where to secure the moulding. Prime and paint the amount of moulding to prevent warping. Cut the moulding to fit on the wall, hold the moulding up to the wall, and mark the locations of the studs. Cut and cope the pieces to fit into corners and with the other pieces of moulding. Nail the moulding in place.
Install the first length of moulding opposite the wall. As the first piece, it has two square ends and looks the best. Two of the lengths of moulding have one square end and one coped end. The last piece of moulding has two coped ends. Typical installation involves mounting it on the same wall as the door.
To avoid the wood splitting, drill pilot holes the same diameter as the intended nails along the stud markings of the moulding. Drill three holes: one at the top of the moulding, one at the bottom of the moulding and a finishing nail hole in the center of it.
The coped joint of the moulding comes in at a 45-degree angle. When laying coped joints, first mark the area with a line, and then use a miter saw to cut this piece of moulding at a 45-degree angle so it fits the existing moulding. For a secure and aesthetic fit, use a coping saw to cut the profile into this angled cut piece.