Overhead Garage Shelves Using Slotted Angle Iron

Goal: Shelves hanging above garage doors.

I have two single garage doors. Each will have 2 – 2′ x 4′ shelves. The material list is for 4 shelves in total.

These are the instructions for building overhead shelves. If you’d like to see an in-depth discussion of the building process and how it relates to agile software development (and see all the mistakes I made along the way), go here.


A hanging shelf is nothing more than a box…or the outline of a box with solid floor.

If you look in the above picture, you will see what I mean. Structurally, this box has a bottom (edges and a floor), sides (just the corner pieces). It doesn’t really have a top, but it has pieces to anchor to that will hold the corners in place.


To make the installation easier to understand, I’ll refer the the shelf with the following terms:

  • Top – Ceiling mounts. The pieces screwed to the ceiling
  • Sides – Corners of the box. Attached to the ceiling mounts and supporting the shelf
  • Bottom – The shelf (plywood) and the 4 side pieces supporting it
  • Back – The part of the box closest to the wall
  • Front – The part of the box farthest from the wall

Material Discussion: I used 1½” 14 gauge slotted angle iron (also called slotted angle steel). It is inexpensive, strong and easy to install. For the floor of the shelves, I used ½” plywood.

I bought the angle iron from Hardware World (they call it slotted angle steel there). I found that ordering the angle iron online was much cheaper (even when paying for shipping) than buying it locally. I also wasn’t able to find any pieces shorter than 36″ locally, but you may have better luck than I.

The hardware and plywood I bought locally.

One thing to note, you can switch up how you mount the shelves to the ceiling. Depending on how your ceiling joists run, you may be able to use smaller pieces. Because of the layout of my garage, I needed to hang the shelves between joists, so I had to anchor pieces wide enough to bridge the gap.

In the image above, these are the pieces that are attached to the ceiling.



Shelf (bottom of the box)

  • 24″ long 1½” Slotted Angle Iron – 2 per shelf, 8 in total
  • 48″ long 1½” Slotted Angle Iron – 2 per shelf, 8 in total
  • 24″ x 48″ ½” Sanded Plywood (one 4’x8′ sheet cut into 4 pieces will do)

Hanging Supports (sides of the box)

  • 12″ long 1½” Slotted Angle Iron – 8 per shelf, 32 in total (used to hang the shelf anywhere from 12-23″ from the ceiling)
  • If you are able to hang your shelves exactly 24″ from the ceiling or need it to be flexible between 24-36″ from the ceiling, you can replace these with 24″ pieces or a mix of 12″ and 24″ pieces

Ceiling Mounts (top of the box)

  • 24’ long 1½” Slotted Angle Iron – 2 per shelf, 8 in total
  • 48’ long 1½” Slotted Angle Iron – 2 per pair (placed above the garage door chain and supports 2 shelves), 4 in total
  • As noted above, if you can run the ceiling mounts along the joists rather than across them, you can get away with smaller pieces


  • 3″ 5/16 Lag Bolts – ~36 (used to attach ceiling pieces)
  • ¾” 5/16 Hex Bolts – ~75
  • 5/16 Nuts – ~75


  • Stud finder (not needed if you have exposed ceiling joists)
  • ½” Wrench
  • ½” Socket Wrench
  • Electric Drill/Driver with socket adapter (makes attaching the lag bolts much, much, much easier)
  • 7/32″ drill bit


Hanging out from the wall

Ceiling Mounts (Top) First

  1. Attach the ceiling mounts to the ceiling using the lag bolts. This will be one 24″ piece and one 48″ piece (the ceiling mounts closest to the wall, farthest from the camera in the top image)
    1. Don’t forget to pre-drill 7/32″ holes.
    2. Attach the back (pieces closest to the wall) first.
    3. Make sure to attach the angle iron with the part hanging down away from the wall (see image 1). This will give you space to attach the hanging supports.
  2. With the back ceiling mounts closest to the wall installed, attach the front pieces.
    1. Measure out a bit more than 24″ from the front edge of the ceiling mount (go 24″ plus 4x the thickness of the angle iron).
    2. Make sure that the part hanging down is in back. What you want is the hanging parts to be just a bit more than 24″ apart.

Hanging Supports (Corners) Next

  1. Install the first two hanging supports on the back ceiling mounts (nearest the wall)
    1. You want the corners to frame the shelf, so make sure that you install the angle iron with one side pointing inward (see image 2).
    2. Using the ¾” nuts and bolts, attach the first 12″ piece to the ceiling mount. Hand-tighten the bolt (you will want everything hand-tight until you are ready to put the plywood shelf in place).
    3. Attach another 12″ piece to the first one you attached. Move it up or down depending on how low you want the shelf to hang. Install the second piece on the inside of the first.
    4. Measure over 48″ and repeat for the second hanging support

Shelf (Bottom) Step 1 Next

  1. Install the first 48″ piece between the back corners
    1. Using the ¾” nuts and bolts, install the piece with one part of the ‘L’ pointing up. This will create a platform for the plywood shelf to sit into later (see image 2).
    2. IMPORTANT – face the bolts outward, meaning put the nuts on the OUTSIDE of the shelf (see image 3). This minimizes the amount of space the bolts take up and allow the plywood shelf to fit easily into the space
  2. Check for level and for square
    1. If necessary, change the height of the hanging supports or move them to the left or right.
  3. Install the other corners, remembering to angle the ‘L’ inward (see image 3)
  4. Install one 24″ shelf support from the back to the front
  5. Try opening your garage door to see if you have enough clearance
  6. If things are ok, install the second 24″ shelf support from the back to the front
  7. Check for level and square

Shelf (Bottom) Step 2 Next

  1. Use a wrench to tighten all the bolts on the back side of the box
    1. You won’t be able to easily reach the back once you put the shelf in place
    2. For now, leave the front side hand-tight. These will be tightened after the shelf is in place.
  2. Before installing the final 48″ shelf support, install the plywood shelf
    1. The shelf will sit on the bottom supports
    2. If you’ve done it correctly, it there will be a 1″ lip where the metal comes up above the plywood. This will keep anything from sliding off your shelf.
    3. Once it is in place, attach the remaining 48″ shelf support
  3. Check for level and square
  4. Use a wrench to tighten the remaining bolts
  5. Repeat for remaining shelves
  6. Enjoy all the extra storage space

If you find this useful, or I’ve missed something, please let me know: david@dfrink.com