Determining Spans and Spacing for Wall Shelves

  • 01 of 08

    Shelf Spans and Vertical Spacing

    Two shelves of tableware
    Jill Chen/Getty Images

    There are two important considerations when installing wall shelves: first, making sure the material used for the shelves has an appropriate span capacity; and second, considering the vertical spacing between the shelves—a decision that is based on the types of objects you will store on the shelves.

    To prevent the shelves from sagging under the weight, you need to know the relative span limitations of different shelving materials. Span in this instance means the distance between supports for the shelf. Span limits are based on the strength of the material—the stronger the material, the more space you can put between wall supports. You may still be able to store fairly heavy objects on shelving materials with a short span limit, but you will need to support the shelf with support brackets that are spaced closer together. 

    Vertical shelf spacing is simply a matter of deciding what you will store on the shelves, and space the shelves accordingly. 

    And remember to fasten your shelf supports directly to wall studs whenever possible. When it is impossible or impractical to attach shelf supports to stud, you must make sure to use the proper wall anchors

    Continue to 2 of 8 below.
  • 02 of 08

    Span Limits

    Wooden shelves mounted on white wall
    Chatuporn Sornlampoo/Getty Images

    The span limit is defined as the maximum distance apart that you can place the shelving supports. Glass, particleboard, solid lumber, plywood, and other common shelving materials can have span limits that can range from 18 inches to almost 5 feet.

    The load that the shelf carries will, of course, affect that allowable span, but for the following span recommendations, it is assumed that the shelf will support a full load of standard-sized hardback books.

    Continue to 3 of 8 below.
  • 03 of 08

    Plywood Shelves

    Shelving full of CDs
    Elizabeth Ellis/Flickr/CC By-SA 2.0

    Plywood for shelves should be 3/4 inch thick or thicker. Standard sheets of plywood come in  1/4-inch, 3/8-inch, 1/2-inch, 5/8-inch, and 3/4-inch thicknesses. Plywood panels over 3/4 inch in thickness are usually special order products. Thinner sheets of plywood can be glued together (laminated) to make a thicker panel for cutting sturdier shelves.

    • The longest recommended span between wall supports for 3/4-inch-thick plywood shelves is 36 inches.
    Continue to 4 of 8 below.
  • 04 of 08

    1 x Lumber Shelves

    Hands measuring and marking wood
    flashgun/Getty Images

    1 x lumber is standard building grade boards, such as nominal 1 x 8, 1 x 10, or 1 x 12  boards. Be aware that the actual thickness of standard lumber is less than the nominal measurement by which it is categorized. All 1 x lumber is about 3/4 inch thick. When choosing 1 x lumber for shelves, it's best to use select-grade lumber, which has fewer knots and other flaws that can weaken the wood.

    • The longest recommended span between wall supports for 1x10 lumber is 24 inches.
    • The longest recommended span between wall supports for 1 x 12 lumber is 28 inches.
    Continue to 5 of 8 below.
  • 05 of 08

    2 x Lumber Shelves

    Ruler and measuring tape
    Getty Images/myshkovsky

    2 x dimension lumber, such as 2 x10s  or 2 x 12s, actually measures about 1 1/2 inches thick. As with 1 x  lumber,  it's best to choose select-grade material has fewer knots and will make stronger, more attractive shelves than construction-grade material. 

    • The longest recommended span between wall supports for 2 x 10 lumber is
      48 inches.
    • The longest recommended span between wall supports for 2 x 12 lumber is 
      56 inches.
    Continue to 6 of 8 below.
  • 06 of 08

    Particleboard Shelves

    A close-up of particle board
    waldenstroem/Getty Images

    Particleboard is a manufactured product that is made from sawdust and other wood by-products bonded together with glues and resins. It is commonly sold in thicknesses of 3/8 inch, 1/2 inch, 5/8 inch, and 3/4 inch. Like plywood, particleboard can be glued and screwed together to create thicker shelves. Single-layer shelving made from particleboard should be at least 5/8 inch thick. 

    • The longest recommended span between wall supports for 5/8-inch particleboard is 24 inches.
    • The longest recommended span between wall supports for 3/4-inch particleboard is 28 inches.
    Continue to 7 of 8 below.
  • 07 of 08

    Glass Shelves

    Home Exteriors & Interiors
    John Keeble/Getty Images

    Spans for glass shelves are based on the type, thickness, and overall size of the glass. Common types of glass for shelves are annealed and tempered.

    Tempered glass is much stronger than annealed, and it breaks into small pieces when shattered, while annealed glass breaks into large shards. Given all the factors involved, it's best to calculate a shelf's weight rating rather than relying on a basic span dimension when installing glass shelves. A glass supplier can recommend a safe weight for the glass you choose. Two examples are provided here: 

    • Maximum weight rating for 1/4-inch-thick x 11-inch-wide annealed glass supported every 24 inches is 29 pounds. 
    • Maximum weight rating for 1/4-inch-thick x 11-inch-wide tempered glass supported every 24 inches is 117 pounds. 
    Continue to 8 of 8 below.
  • 08 of 08

    Recommended Shelf Height Spacing

    A bookshelf covered in books
    See-ming Lee/Flickr/CC By-SA 2.0

    Use the following guidelines to determine the "clear shelf height" needed for the types of items you plan to place on your shelves.  Clear shelf height is the space measured from the top of the lower shelf to the underside of the shelf above it.

    • Paperback books: 8 inches
    • Hardback books: 11 inches
    • Large hardback/coffee table books/catalogs: 14 inches
    • Magazines: 14 inches
    • CDs: 5 inches
    • DVDs (movie cases): 8 inches