Hyderabadghar/Do it your self/Casing a Door

Interior door casing can be simple or complex depending on the wood, joinery, and detailing, and can be manipulated in dozens of ways. Head casing is the horizontal member that spans the top of the door frame. Side casing consists of the trim on either side of the door. Like the head casing, side casing is nailed into the edge of the door frame. There are several ways to join the head and side casings around a door (Fig. 1). For example, decorative corner blocks can unite the head and side casings, and plinth blocks can be used at the bottom of the side casing where the baseboard meets the door trim. Yet the most common method is to use a miter joint, which is simply two adjacent 45-degree angles which form a 90-degree angle. Joining door casing using this method is described below.

Fig. 1

PROJECT BASICS

Project: Moderate
Estimated Project Time: A weekend
Start Tips: Make sure the door opening is square
Safety Tips: Wear a dust mask while cutting wood to protect your lungs from sawdust
Recommendation: Do-it-Yourself

TOOLS & MATERIALS

Combination square	Hammer
Pencil	Circular saw with jig, table saw with jig, or power miter saw (which can be rented)
Lumber for door casing	Measuring tape
Nails	Safety goggles
Nail set or a 10d nail	Dust mask

Fig. 2

INSTRUCTIONS

1) Mark the reveal
The inside edge of the casing should be offset from the inside edge of the jambs by approximately 3/16 inch. The small edge caused by offsetting the two is called a reveal. Set the combination square for 3/16 inch and use it to guide your pencil around the jamb, leaving a line 3/16 inch from the edge. (Fig. 2)

Fig. 3

2) Cut and miter the first length
Cut a length of casing square at one end. Then place the casing against the reveal line and square cut it where it meets the floor. Mark the casing at the point where the vertical and horizontal reveal lines intersect, and cut a 45-degree angle at this point. (Fig. 3)

Fig. 4

3) Install hte first length, cut the second
Nail the first piece of casing to the jamb with 3d or 4d casing nails spaced every 12 inches or so. Now cut a 45-degree angle on another piece of casing, fit it against the side casing, mark it for the opposite 45-degree angle, then cut and install it. (Fig. 4)

Fig. 6

5) Set the nails
After nailing the casing in place, set all the nails just below the surface of the wood. Use a nail set and a lightweight hammer to set the nails. If you don't have a nail set, substitute a 10d nail for one, and use it carefully.

Next, fill the holes with wood putty and sand them smooth when dry. (Fig. 6)