Things You'll Need
Utility knife or hand rooter
Flat pry bar
3-inch flashing, if needed
Exterior grade panel adhesive
10D galvanized casing nails
Nail set tool
Exterior grade wood filler
Paint or stain
How to Replace Brick Molding. Brick molding has no brick in it. It is the molding around your exterior doors and is usually made out of wood. Brick molding can rot and then needs to be replaced. You can handle the replacment process yourself.
Remove the Old Brick Molding
Use a utility knife or a hand rooter to cut through the caulk between the molding and the siding to loosen the molding, being careful not to make any cuts on the siding.
Remove the nails in the corners of the brick molding with the claw of a hammer.
Loosen the molding with a flat pry bar and remove.
Remove the drip edge at the top of the door if it needs to be replaced by pulling it down from behind the siding and discard. Use gloves so you don't cut your hands on the edges if the drip edge is metal.
Inspect the area behind the molding to see if there are any rotten boards that also need replacing.
Replace the Old Brick Molding
Measure out a replacement piece of molding slightly larger than you need. Hold it up to the opening and mark where it needs to be cut to fit. Cut along the lines with a miter box and test measure after cutting to make sure the piece will fit.
Replace or install new drip edge at the top of the door if desired by cutting a 3-inch wide piece of flashing at the length to fit across the entire top. Lengthwise, fold the flashing in half and slip it underneath between the siding and the building paper with the folded edge down. No nails are required for this step.
Apply exterior grade panel adhesive to the back of the molding with a caulk gun and fit the molding into place. Allow to set per the adhesive manufacturer's directions.
Nail the molding together where the cut pieces meet on each side of the door with 10D galvanized casing nails. Set the nail with a nail set tool so the nail goes into the wood of the molding.
Use an exterior grade wood filler to fill in the holes over the set-in nails.
Seal the joints and the edges where you removed the original caulk with exterior caulk that can be painted.
Prime and paint or stain the new molding.
A drip edge, located behind the brick molding at the top of the door, is used to allow water to run off and to the side to keep moisture off the brick molding. You shoudn't replace the old drip edge unless it needs it. You can use the old piece of drip edge as a guide if you have one to cut your new piece. Most exterior molding is pre-primed; however factory primer doesn't work as well as when you prime it yourself.
Remove and replace the molding carefully so you don't damage your siding.