How to Install a Built-in Corner Desk

Measure the length and width of the desk top you are going to install. If it is an L-shape desk top, measure the length of both arms of the L, and the width of the desk top. If it is triangular, then measure the length of the two wall sides of the triangle, and the width of the desk top approximately a foot in from each end of the triangle.

Mark a level line on the wall as long as the length of the desk top in the corner where you will install the desk, to mirror the eventual position of the desk top on the wall. Mark the location of the wall studs on the line using a stud finder.

Cut two pieces of 2-by-2 lumber to approximately 5 inches less than the length of the desk sides for wall cleats. Cut two pieces of 2-by-2 lumber about 5 inches less than the width of the desk top for the horizontal arm of the wall brackets, and another two pieces about 5 inches less than the distance between the wall line and the floor for the vertical arms of the wall brackets.

Position the wall cleats on the level line, with the ends about 2 inches in from the corner. Secure the cleats in place with two 3-inch drywall screws driven through the cleat at every wall stud position.

Position the two vertical arms of the bracket upright abutting the edge of each cleat at the ends. Secure them to the wall with 3-inch drywall screws every five inches down the bracket arm. If the desk top is triangular, then position the arms from where you took the width measurement.

Cut out two triangles of 3/4-inch plywood that has one side as long as the distance between the cleats and the floor, and another side as long as the width of the desk top. For a triangular desk top, then cut out a 2-inch square from the right corner of the triangle to accommodate the cleat.

Abut the triangle's desk-to-floor side along the vertical arm of the bracket, so that the corner is flush with the top of the cleat. Place the horizontal bracket arm on the width side of the triangle, abutting the cleat. This will mean there will be approximately 2 inches between the end of the horizontal bracket arm and the side of the triangle touching the wall.

Mark the position of the horizontal arm, then remove and secure the arm to the triangle with 2 5/8-inch wood screws. Replace the triangle bracket with the horizontal arm attached in position, and attach it to the end of the cleat and the side of the vertical bracket arm with 2 5/8-inch wood screws. Repeat on the other end of the desk.

Glue a strip of solid wood molding to the exposed edge of the triangle bracket to hide the cut edge of the plywood.

Place the desk top over the wall cleats and brackets. Use 2 5/8-inch wood screws to attach the desk top from the underside of the cleats and the horizontal bracket arms, so that no screw holes mar the surface of the desk top. Paint the brackets to match the desk top.