Home & Garden Architecture

DIY: Floating Shelves for an Alcove

By Home & Garden Last updated Saturday, May/25/2024

Measure and Cut

1). Measure the width and depth of your alcove.
2). Cut one pine beam to a length equal to the width of your alcove. Cut the other two beams to a length equal to its depth, minus 1-1/2 inches. An alcove 36 inches wide and 24 inches deep would require one beam 36 inches long and two beams 22-1/2 inches long.
3). Cut two furring strips to match the depth of the alcove, minus 1-1/2 inches. Cut the other two strips to match the width, minus 5 inches. The alcove above would need two furring strips 22-1/2 inches long and two furring strips 31 inches long.
4). Cut the two plywood sheets so that both exactly match the width and depth of your alcove.
5). Sand all faces of the lumber until they're smooth to the touch.

1). Set the four furring strips in a rectangular frame. The ends of the width-cut strips should abut the inside faces of the depth-cut strips. All strips should rest on their narrow, 1-inch wide edges.
2). Glue one corner in place and reinforce it with two nails from a nail gun. Wipe off the excess glue and allow it to dry.
3). Repeat Step 2 for the other three corners of the frame. You may go quicker if you work on other corners while the glue dries on the first one, but the dried glue can add some stability that will make the job easier.
4). Set one plywood sheet in place on top of the frame. One of its width-cut edges should align evenly with the outside edge of one width-cut furring strip. The other three edges should overlap the other strips by 1-1/2 inches.
5). Glue the sheet in place along the tops of the furring strips. Reinforce it with one nail in each corner and one nail for every 3 inches along each furring strip. Wipe off the excess glue and allow it to dry.
6). Turn the shelf over and repeat Steps 4 and 5 to attach the remaining plywood sheet to the open face of the frame.
7). Paint the plywood and visible side of the front furring strip. For best results, use long and even strokes in the same direction as the grain of the lumber. Allow it to dry. You may need multiple coats to get the color you want.

1). Use a stud finder to locate the studs in all three walls of your alcove. Mark their locations with a pencil.
2). Draw a line on the back wall of the alcove at the height you want the shelf. Use a level as a straight-edge and to make sure the line is level. Do the same for both side walls.
3). Set the width-cut beam against the back wall with its top edge lying along the pencil line. Screw it in place with one 4-inch wood screw for each stud it crosses.
4). Install the depth-cut beams on the side walls using the same method you did in Step 3.
5). Slide the shelf frame over the beams you've attached to the walls. The three open sides should fit over them snugly.
6). Screw the shelf in place with two 1-inch wood screws evenly spaced along each of the three beams. Screw through the top of high-mounted shelves and through the bottom of low-mounted shelves.