Shelving shouldn’t sag or bend under the weight of a load. The guidelines
and chart below will help you select the appropriate materials for your project.
Note that there are a number of ways to deal with a too-heavy load: you can
reinforce the shelf, change the material you construct it of, choose a thicker
or wider piece of stock, or shorten the span. The general guideline is: the
thinner, the narrower in width, and the longer the piece of stock, the more
apt it is to bend.
Lumber: is the most rigid material and therefore least
apt to bend under loads.
Plywood: is less rigid than lumber and thus more apt
Particle board and hardboard: are least rigid and are
thus apt to bend or even break under loads.
In designing a shelf, consider not only the weight (load) but
also how it will be distributed, and select a shelf design, a
construction method, and materials that have sufficient rigidity
to avoid sagging. The potential for sagging will vary with the
way the load is placed on the shelf.
Ways to Reinforce a Sagging
Be conservative in deciding the length of shelf spans; if there
is a possibility of sagging, use one of the reinforcing methods
Apply lumber to one or both long edges.
Add mid-span supports as needed.
Add support around shelf edges.
Table below shows: Load Capacities
Light Load -- yellow dot -- (10 - 15 pounds. Example: towels.)
Average load -- black dot -- (15 to 25 pounds. Example: mix of
canned and boxed food staples.)
Heavy load -- red triangle -- (25 to 50 pounds. Example: LPs,
Reinforce -- R -- (You’ll need to reinforce a
shelf of these dimensions.)
Next: Sizing Up Your
ALL ARTICLES in this Guide:
DIY and Custom-Made Storage Solutions:
Components You Can Build for Home, Office ... as a Hobby or for Sale
(Profit, earn Income)
Doors, and Toes
- Tools, Techniques, and
- Spans and Loads
- Sizing Up Your Space
- Layout and Cutting
- Cuts and Joints
- Detail Milling and
- Drilling and Fastening
- Gluing, Clamping,
- Doors and Drawers
- Face Frames and
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