How to Install Door Casings & Rosettes Using Glue

Measure the door opening along the sides and top. Make the side measurements from the floor up to the bottom edge of the door opening. This is the length required for the two side door casing boards. Add two times the width of the casing to the width of the opening at the top of the door to get the length required for the top (head) casing board.

Lay the casing boards flat, one at a time, on the table of the miter saw. Measure the boards and mark them to the lengths you measured and calculated in Step 2. Mark two side casing boards and one top (head) casing board to length.

Slide each board across the table of the miter saw until the pencil line is lined up with the outside edge of the saw blade. Pull the trigger and guide the saw down through the casing to complete each cut. Lift the saw up and release the trigger.

Trim off the tip of the adhesive tube at a 45-degree angle with the built-in cutter on the caulk gun. Puncture the seal in the tip of the tube with the puncture tool on the caulk gun. Place the tube tip-first into the caulk gun.

Apply a bead of adhesive along the back of each piece of side door casing in a zig-zag pattern. Press the side casing boards into place against the sides of the door opening. The inside edge of the casing boards should be flush with the edge of the door opening.

Put the adhesive along the back of the top (head) casing in the same manner that you did in Step 5 on the side casing boards. Center the top (head) casing over the top of the door opening. The bottom edge of the casing should rest flush on the top ends of the side casing. Press the casing board into place.

Apply adhesive to the back of each rosette block and press them into place in the top corners of the door casing. The outside edges of the rosette blocks should be flush with the outside edges of the casing.