[Execut1ve]

Hello all,

I am in the process of designing a set of shelves to hold books & some other lighter items. Span will likely be in the neighborhood of 30". These are intended to be fixed shelves attached to the wall, so I imagine the rear of each shelf will be anchored at intervals. Shelf depth will be 11-12".

What materials should I be considering to keep the sag reasonable, if not minimal? I haven't used a ton of different materials in the past, so I'm unfamiliar with the virtues of different types of wood. I have used Lowes' "whitewood" pine boards and 1/2"-3/4" plywood, but I imagine this application might call for something sturdier.

thanks for reading!

 

[4DThinker]

Hardwood will sag the least. Hardwood plywood like Baltic Birch, then lesser sheet goods, then plastic no matter how well it looks engineered. In other words, plastic makes horrible shelves.

Different hard woods have different degrees of flex under the same load. A good reference: http://workshopcompanion.com/KnowHow/Wood/Hardwoods_&_Softwoods/1_Wood_Botany/1_Wood_Botany.htm
More specific table: http://workshopcompanion.com/KnowHo..._Properties/Mechanical_Properties_Table_1.htm

 

[RogerInColorado]

4DThinker, thanks for your two side suggestions. I especially like the second one.

Execut1ve, I recommend the Sagulator. It lets you pick a species, plug in your values then computes sag. It's a fun calculator to experiment with different woods and shelf thicknesses and depths, etc. and pretty accurate:

http://www.woodbin.com/calcs/sagulator.htm