How to Build Sturdy Shelves in an Alcove

Measure the height and width of the available space in the alcove. Measure the height from floor to ceiling, and measure the width from right-hand wall to left-hand wall as you face the end of the alcove.

Measure the depth of the alcove from the closed end to the edge of the available floor space at the open end. Write down all your measurements.

Use a stud finder to find all studs in the three walls of the alcove. Use a pencil to mark the position of all the studs at shoulder height.

Measure the height, length and width of all the articles you need to store. Mark a point on each stud on the wall at the end of the alcove, two inches taller than the height of the tallest object you intend to store.

Have a helper hold one end of a chalk line along one series of the marks you just made on each of the alcove walls, while you hold a spirit level in place along the underside of the line. Adjust the position of the chalk line until all the air bubbles in the spirit level fall between the lines in each bubble chamber. Snap the chalk line. Repeat this process for each series of marks you made on each wall of the alcove.

Make a rear shelf support cleat for each shelf that you will fit against the wall at the end of the alcove. Use 1-by-2-inch stock lumber, cut to the length needed to fit along the chalk lines on the rear wall of the alcove. For example, if the rear wall of the alcove is 5 feet wide, cut the stock lumber to 5-foot lengths to make rear shelf support cleats to fit across the end of the alcove.

Have a helper hold each piece of cut stock lumber against the alcove's rear wall, along the chalk lines. Drill 1/16-inch-diameter pilot holes along the 2-inch face of each piece of stock lumber, at the center point of each wall stud, through the stock lumber and into the stud.

Countersink all holes by placing the tip of the countersink bit in the pilot hole. Drill into the holes just enough to seat the head of the screws even with the surface of the shelf support cleats.

Secure the shelf support cleats to the wall, using 2-inch-long, 1/8-inch diameter wood screws.

Cut two side support cleats for each shelf, the same length as your arm from shoulder to fingertips, plus whatever additional length is needed to reach from the back wall to the first two studs on each side wall. Use 1-by-2-inch stock lumber. Attach them to the side walls of the alcove, butted against the back wall, using the method described in Steps 7-9.

Mark each wall stud 18 to 24 inches above the chalk line for the first shelf, and snap a second chalk line. Repeat for each additional shelf you intend to make in your alcove.

Cut the first shelf from 3/8-inch-thick plywood. Make its length equal to the width of the closed end of the alcove and its width equal to the length of your arm from shoulder to fingertips.

Place the shelf on the support cleats.

Measure from the underside of the shelf to the floor, and cut one or more pieces of 2-by-4-inch stock lumber to serve as support posts. Give shelves longer than 34 inches at least one support every 16 to 20 inches to prevent sagging.

Position the support posts under the shelf every 16 to 20 inches. Adjust the positions of the support posts so that a 2-inch side faces you, flush with the edge of the shelf.

Drill a 1/16-inch-diameter pilot hole one inch from the edge of the shelf, through the plywood and into the post. Drill a second hole three inches from the edge of the shelf, and countersink the holes.

Secure the shelf to the support posts using 2-inch-long, 1/8-inch diameter wood screws.

Cut additional shelves and support posts as needed, securing them the same way.

Smooth each shelf using a belt sander with coarse through extra-fine belts. Seal the shelves with three coats of clear acrylic wood sealant, allowing it to dry overnight between coats.