Slide a stud finder along the wall above the washing machine until it indicates a stud location. Mark the location of the stud onto the wall with a pencil. Repeat for the second stud.
Position the two shelf brackets against the wall at the two stud markings spaced 32 inches apart. Hold the brackets at the height desired for the shelf. Place a level across the brackets. Adjust the brackets so that they are level. Mark the mounting hole locations in the brackets onto the wall and set the brackets aside.
Place each bracket against the wall, one at a time, and align the mounting holes up with the markings on the wall. Drive the screws included with the brackets, through the mounting holes into the wall with a drill or screw gun to mount the bracket to the wall.
Lay the hardwood board on a clean work surface. Brush on two coats of wood finish onto the hardwood board using a paintbrush. Allow the first coat to dry at least four hours before applying the second coat. Wait 24 hours after the second coat before continuing with the project. Turn it over and do the other side in the same manner.
Center the hardwood board over the brackets. Drive the screws included with the brackets for attaching the shelf through the mounting holes in the brackets into the bottom of the board with a screw gun.