Projects
Installing Door Trim
Project Overview
The trim itself consists of the head moulding, which goes across the top of the doorway, and the legs, which run from the floor to the head moulding. First, mitre the joints between the head and legs. A common approach is to put in the head moulding first so you can cut the legs to length without a lot of measuring. The mitred scraps that you clamp in place instead of the legs simplify laying out the two mitres on the head moulding.
6 Steps
- LAY OUT THE REVEAL
- PUT UP TEMPORARY SUPPORTS
- MEASURE THE LENGTH OF THE HEAD MOuLDING
- MITre ONE END OF THE HEAD MOuLDING
- MITRe THE HEAD MOuLDING TO LENGTH
Step 1
LAY OUT THE REVEAL
Lay out the reveal. The trim sits back from the edge of the door jambs by a space that's called the reveal. Lay out the reveal, which is usually 1/8-inch, with the help of a combination square. Set the square so the blade sticks out from the body of the square by 1/8-inch. Put the body of the square against the jamb, and a pencil against the end of the blade. Slide the body along the jamb to draw a line the full length of all three jambs.
Step 2
PUT UP TEMPORARY SUPPORTS
Put up temporary supports. Mitre two scraps of moulding at a 45-degree angle. Tack or clamp them in place, positioning them as if they were the upper ends of the leg mouldings. Align them carefully with the reveal lines, and make sure the inside corner of each mitre is on the corner created by the lines.
Step 3
MEASURE THE LENGTH OF THE HEAD MOuLDING
Measure the length of the head moulding. Measure from point to point on the temporary supports to get the length of the head moulding, sometimes called the top moulding or head casing. Double-check by measuring between inside jambs at top of opening, and adding 3/8 inch the combined distance of the reveals.
Step 4
MITre ONE END OF THE HEAD MOuLDING
Mitre one end of the head moulding. Put the head moulding in place, and sketch in the general direction of the mitresdon't worry about the true length or the exact angle of the mitre at this point. Set the mitre saw to cut a 45-degree angle. Cut one 45-degree mitre in one end of the moulding, following the general direction of the line.
Step 5
MITRe THE HEAD MOuLDING TO LENGTH
Mitre the head moulding to length. Measure along the edge of the moulding from the point of the mitre to the desired length of the head moulding, and make a mark. Mark the face of the moulding at the same point, and mitre the moulding to this length, following the general direction of the line you drew earlier.
Step 6
NAIL THE HEAD MOuLDING IN PLACE
Nail the head moulding in place. Rest the head moulding on the scraps, and adjust the scraps if necessary so the moulding follows the reveal and is centred over the doorway. Nail the bottom of the moulding to the jamb with 3d or 4d nails driven roughly every 12 inches. Drive 6d or 8d nails through the top of the moulding into the framing. Keep the nails at least 1/4 inch from the edge of the moulding and 1 inch from the ends to prevent splitting. Remove the scraps and install the legs.
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