How to Install Wood Window Cornices

Place a sturdy step ladder on the floor in front of the window. Locate two wall studs, one on each corner above the window if the cornice is less than 6 feet wide. However, for boards wider than 6 feet, locate three studs, one on each end of the window, and one in the middle. Mark stud locations with a pencil.

Center the cornice in place, with its upper edge above the window and its bottom hanging slightly below the window top. Set a carpenter’s level on the upper edge of the cornice board and adjust it as needed until the bubble on the indicator reads plumb. Hold the cornice steadily while you mark its placement on the wall, using a pencil.

Hold an inverted L-bracket on one end of the wall, so it resembles the number 7. Ensure the top of the bracket falls flush with the pencil mark.

Insert the tip of a pencil through the bracket holes to mark the locations for screws on the wall. Repeat the process with the other corner bracket, and one in the middle if the cornice is wider than 6 feet.

Drill holes through the pencil marks on the wall. Drive 2-inch screws into the holes using a screwdriver to secure the L-bracket to the wall. Repeat the process of securing the other L bracket.

Set the wood cornice over the L-brackets to check whether they hold weight securely. If required, secure an additional bracket along its width.

Mark spots on the wood cornice where you will drill holes into it. Set the cornice down -- and using a drill bit slightly smaller in diameter than the width of the mounting screws provided with the L-brackets, drill into the inside of the wood cornice. Work carefully to avoid drilling all the way through the front of the cornice, or tearing through the fabric covering its front.

Set the cornice back over the brackets. Drive screws into the holes to secure the cornice to the brackets.