How to Frame a Flat Bathroom Mirror

Measure your mirror’s length and width. Cut two lengths of molding to match the height measurements and two to match the width measurements. Miter the end of each cut piece to a 45-degree angle. Route a 2-inch-wide notch along the thickest, longest edge of each piece. This notch will allow you to fit the molding around the mirror instead of just on top of the mirror.

Dry fit the molding around the mirror. Note the location of the plastic clips, if applicable. Use a chisel to carve out spaces for them in the back of the molding where necessary.

Place a length of molding on top of the two blocks. Paint or stain the molding and allow it to dry. Turn over the molding, and cover the other side. You must paint or stain both sides of the molding, since the mirror will reflect the back edge of the molding once attached. Repeat this process with the remaining three lengths of molding.

Run a bead of silicone caulk along the notches you routed in the back of the molding pieces. Attach the molding along these edges to the face of the mirror. If the corners don’t exactly meet, fill the open spaces with caulk. Allow the caulk to dry completely before proceeding.

Nail the outside edges of your molding to the wall behind them to further secure your mirror frame. Countersink the nails to make them easy to hide.

Cover your nail holes with a dab of wood putty over each cavity. Use a flat edge to wipe away excess putty, and sand the areas smooth once they’ve completely dried. Touch up these areas with the same paint or stain you used to initially cover the moldings. Also cover the caulked corners with paint, if necessary.