Shelf Length vs. Sag

[GrayFox]

For solid wood shelves, what are the guidelines for shelf length vs. sag?

[David]

check out the "sagulator" on the web.

[Upscale]

When it starts to sag it's too long?

Really now. You haven't said how thick you were thinking of making the shelves. You haven't said what you might make them out of. You haven't said what type of shelf construction you have in mind and you haven't said what you might be putting on these shelves.

How do you expect anyone to answer your question?

[Robert Allison]

The longer the shelf, the more the sag.

But you probably figured that out for yourself!

I don't like to make shelves longer than 30 inches or so out of anything. If I have to go longer than that, then I like to put a horizontal support under the front edge, or add another vertical stile. You could also increase the thickness of the shelf, but that may not be practical, although a 3/4" shelf with a horizontal stiffener looks like a thicker shelf.

[David]

you can stiffen a shelf in a number of ways.

reduce length and or increase thickness

secure along the back edge

include a "stiffener" --front edge trim thicker than the shelf itself

gluing it into a dado on back edge and sides will increase it's load carry capacity over a "loose" shelf

species of wood matters. MDF, ply, solid wood all have different sag factors.

Dave

[Battleax]

For 3/4" material stay under 24"

[GrayFox]

You're exactly right on all accounts! I was thinking of 3/4" thick material made from alder. The shelves will me held up by the little adjustable thingees that fit into the holes drilled into the side panels. I'll be putting anything from office supplies to books on the shelves.

I hope noe somebody can give me an answer. :)

[GrayFox]

bookmarked!

[TomWoodman]