How to Install a Shelf From Basement Rafters

Cut two side supports from the 1-by-6 board. Measure the height of the items you wish to store on the shelf and add 4 inches to the measurement. So, if you want to store 12-inch-tall detergent boxes on the shelf, cut two 16-inch-long side supports.

Measure 1 inch up from the bottom edge of the first rafter you wish to hang the shelf from, near the wall, and make a mark. Position the short side of the shelf support against the side of the rafter, aligned with the 1-inch mark. Select the second rafter and repeat this process.

Insert one screw, centered from side to side, 1/2 inch from the top edge of the shelf support and into the rafter. Repeat for the second shelf support. You will now have two hanging pieces of wood and will secure the shelf between them.

Measure the distance between the shelf side supports; cut a board to this length for the shelf surface. Position the board at the bottom of the shelf side supports. Insert a screw through the middle of the shelf support into the end of the shelf. Repeat for the other side of the shelf but before inserting the first screw, check that the shelf will sit level from end to end. Adjust the board as needed and insert the screw.

Use a level to adjust the shelf so that it's level from front to back. Because you only inserted one screw at each position, you can twist the boards in several different ways to achieve a level shelf surface. Once you've leveled the shelf, insert two more screws at all four connection points -- two points at the rafters and two at the ends of the shelf.