How to Build a Floating Corner Shelf

Corner Shelf

Brett Taylor / Getty Images

In This Article
Project Overview
  • Working Time: 2 - 4 hrs
  • Total Time: 2 - 4 hrs
  • Yield: Corner shelf 40 inches by 9-1/4 inches
  • Skill Level: Advanced
  • Estimated Cost: $40 to $60

So-called floating shelves, sometimes known as cantilevered shelves, are supported by invisible support bracing rather than by the visible brackets or braces that usually support wall shelves. The concept of the architectural cantilever is an emblem of modern design; its influence is found in many aspects of contemporary style. When manifested in the from of a floating shelf, it offers a simple design elegance that can work in any room of the house, especially those with modern decor.

Appearing to float effortlessly from the wall, this corner version is perfect for small, lightweight items that you cherish and want to display, such as flowers, glassware, pottery, small plants, and photos.

Before You Begin

This floating shelf design is constructed by first building and attaching a pair of wall cleats with a modified "E" shape into the corner of the room at the desired height. Then, the cleats are boxed in with prefinished top and bottom boards, and the edges are covered with finished trim pieces so that the cleats become entirely hidden. It is important that you anchor the cleats solidly to wall studs; this is essential to maintaining the strength of a cantilevered shelf.

You could run into a complication if your room corner is not exactly square, as is often the case, especially in older homes. This may prevent the corner shelf from fitting tight against both walls as you install it. If this occurs, it is relatively easy to fill any gaps between the back edge of the shelf and the wall with paintable caulk.


One Thing Ep 90: These Simple Shelves Make a Big Impact

Safety Considerations

While this corner shelf is sturdier than most cantilevered shelves, no floating design should be used to support heavy items. Heavy books, appliances, office equipment, and other weighty items should be kept off of this shelf.

What You'll Need

Equipment / Tools

  • Tape measure
  • Pencil
  • Power miter saw
  • Stud finder
  • Screw gun
  • Speed square
  • Level
  • Drill and 1/8-inch twist bit
  • Brad nailer
  • Spring clamps


  • 1 1x3 common lumber (pine or fir), 8 ft.
  • 1 2x3 common lumber, 4 ft.
  • 1 1x3 white primed trim board, 8 ft.
  • 2 1x10 white-primed trim boards, 6 ft.
  • Wood glue
  • 1 2 1/2-inch screw


  1. Prepare the Pieces

    Use a miter saw to cut the pieces for the hidden cleat assemblies and the top and bottom shelf surfaces as follows:

    • From 1x3 common lumber (spruce or fir), cut two boards—one at 40 inches long, and another at 39 1/4 inches. These will be the wall cleat pieces for the cleat assemblies.
    • From 2x3 common stock, cut six pieces, each 8 inches long. These will be the perpendicular arms for the wall cleat assemblies.
    • From 1x10 white-primed trim board stock, cut two pieces at 40 inches, and two pieces at 30 3/4 inches. These will be the top and bottom shelf surfaces that will be boxed around the wall cleats.


    If you are adapting this design to create a shelf with different dimensions, keep in mind the difference between the nominal dimension (how it is labeled and sold) and the actual dimension of lumber stock. For example, a 1x3's actual dimension is 3/4 x 2 1/2 inches. Very careful sketching will help you accurately plan a shelf of any size you choose.

  2. Assemble the Cleats

    Begin by building the right side cleat. Position the 40-inch long 1x3 on edge on a flat surface, then position three 2x3 cleat arms on edge against the face of the wall cleat, so they extend out at right angles. Beginning from the left, the first arm should be spaced 10 inches from the end of the wall cleat, the second arm at 24 inches, and the third arm should be set back 3/4-inch from the right end of the wall cleat. (This recess will allow for the installation of a trim piece).

    To attach each perpendicular arm, apply wood glue to the ends of the arm, then position it so it is exactly perpendicular to the wall cleat, and secure it with a pair of 2 1/2-inch screws driven through the back face of the wall cleat and into the end of the arm. As you attach the arms, use a speed square to make sure they are exactly perpendicular to the wall cleat (this is essential).

    Repeat the process with the 39 1/4-inch wall cleat, except in this case begin the measurement from the right side, so that it's the left-side arm that has a 3/4-inch setback from the end of the wall cleat.

    You now will have two E-shaped wall cleats assemblies ready for installation.


    Some builders may want to reinforce the inside corners of the cleat assembly with metal L brackets to create extra-strong joints. This might be a good idea if you anticipate using the shelf to support moderately heavy objects.

  3. Locate the Studs

    Use a stud finder to identify the four studs where you will anchor the wall cleats—two on each side of the corner junction. In normal wall construction, the studs will be located at 16 inches and 32 inches from the corner, though this can vary. Mark the studs at the height where you want to hang the shelf. Use a carpenter's level to extend level guidelines out from the corner, indicating the top of the wall cleat.

  4. Attach the Right Cleat

    Position the 40-inch wall cleat assembly on the right side of the corner so the top edge is aligned with the marked reference line on the wall. Drill pilot holes then drive 2 1/2-inch screws through the wall cleat and into the studs. Drive two screws per stud, for a total of four screws. The cleat assembly will jut out from the wall, parallel to the floor.

  5. Attach the Left Cleat

    Place the 39-1/4-inch cleat assembly on the left side of the corner, butting its end against the right-hand cleat. Make sure the cleat is level. As you did with the right cleat, drive two screws into each of the two studs.

  6. Attach the Shelf Top and Bottom

    Attach one of the 40-inch and one of the 30-3/4-inch 1x10s to the top of the cleats to form a 90-degree angle, using a brad nailer. The 1x10s should overhang the cleat arms by at least 3/4 inch, creating the space for the trim pieces that will be installed later.

    Repeat with the other pair of 1x10s to cover the bottom of the cleat assemblies. You can hold the bottom boards in place with spring clamps while you attach them to the cleat assemblies.

  7. Cut the Edge Trim Pieces

    Measure and cut side and front trim pieces from 1x3 trim boards. The wall ends will be cut at 90 degrees to fit flush against the walls, but the two outside corners and the inside corner will be mitered at 45 degrees to create perfect mitered joints. Make sure to measure and cut carefully, as it is easy to make mistakes when cutting mitered corners.

  8. Attach the Edge Trim

    Position and attach the edge trim pieces one at a time. The trim pieces should fit so they are sandwiched between the top and bottom shelf surfaces, flush with the edges. Hold the trim pieces in place with spring clamps as you attach them with brads driven vertically through the top and bottom shelf surfaces and into the trim pieces.

  9. Complete the Finishing Touches

    If you wish, you can fill holes where the brads were driven with wood filler. If necessary, any gaps along the wall joint (common if your walls aren't perfectly square) can be filled with paintable caulk.

    If necessary, use paint to touch any spots that require it.

  • What angle do I cut for a corner shelf?

    The angle depends on how you want your corner shelf to look. You can put the pieces together at a 90-degree angle with straight cuts. Or you can cut each piece at a 45-degree angle, so they fit together in the center of the shelf.

  • How do you support a corner shelf?

    The shelf can be supported by simple E-shaped wall cleats. You also can use metal L brackets to strengthen the joints when hanging the shelf, especially if you plan to put heavy items on the shelf.

  • Is it cheaper to build your own shelf?

    It usually is cheaper to build your own shelves, especially if you want custom shelves. But this can vary depending on the type of wood and other materials you use.