What is the minimum dimension for ends and back cleats in closet shelves with an attached rail?

The minimum dimension for ends and back cleats in closet shelves with an attached rail is at least 3/4" × 3 1/2". This specification is important for ensuring the structural integrity and stability of the shelves. The dimensions provided allow for adequate support; the thickness of 3/4 inch ensures that the cleat can effectively bear weight without bowing or breaking, while the 3 1/2 inch width provides sufficient surface area for attaching to the shelf or rail system securely. This configuration helps maintain alignment and supports the overall load that the shelf is expected to carry.

Other options outline alternative parameters or conditions that do not align with this specific requirement. For instance, stating "on all sides" doesn't specify dimensions and could lead to ambiguity regarding how the cleats should be constructed. Suggesting a build with "at least 2×4 material" prescribes a different, larger material that may not be necessary or practical for all closet shelf applications. Lastly, the option that suggests "all of the above" is misleading since not all provided information pertains to the specific minimum dimension required for cleats.