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Jeff Vandenberg
1350 posts
and
51 followers
in almost 10 years
in almost 10 years
Shelving Spans for Bookcases
Shelving Spans for Bookcases(copy right handyman magazine )
If you’re designing a cabinet or a bookcase, what’s the greatest length (span) a shelf can be without an objectionable sag? There are four factors to consider: 1) how the load is distributed, 2) the expected load, 3) the shelf material, 4) the method of reinforcement.
GUIDELINES. Taking the four factors into consideration, the chart shows some general guidelines for the maximum span for shelves to avoid objectionable sag. Note: The most practical approach is to use 4/4 stock or plywood with reinforcement. This will produce shelves with minimum sag and the best visual appearance.
MAXIMUM SPAN FOR 10" WIDE SHELF FULL OF BOOKS
Shelf Material Maximum Span
3/4" Particle Board 24"
3/4" Plywood 30"
4/4 (13/16") Solid Stock 36"
6/4 (1-5/16") Solid Stock 60"
3/4" Plywood Reinforced with:
1-1/4" wide face strip on edge 36"
1-1/4" wide face strip on side 32"
Aluminum strip underneath 36"
Molding strips underneath 36"
Jeff Vandenberg aka "Woodsconsin"
3 Replies
I personally like to use tongue and groove while reinforcing with the strip on edge.
Abbas, Castro Valley, CA
And the entire game changes when you secure the shelf to the back of the cabinet, then add a stiffner to the front, which can improve the look, as well as allow heavier loads.
On a whim, I built a bookshelf from 3/8" ply. It is about 30 inches wide, loaded with books, and there is no wow, for the reasons noted above.
On a whim, I built a bookshelf from 3/8" ply. It is about 30 inches wide, loaded with books, and there is no wow, for the reasons noted above.
The Sagulator can be pretty handy when trying to make sure you do not have too much sag on a span. It will take into account the material and thickness, span, width, whether it has an edge strip and its material and how the load is distributed and how much. It will also take into account whether the ends are attached or floating as in adjustable shelves.
--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.
