Red Oak Shelving Strength??

[DD716TED]

I would like to make a shelf to connect two pieces of an entertainment center (bridge over TV) connecting the two side shelf units. I would like to use solid oak (not veneer over plywood).. .QUESTION: if the shelf is made from 1 x 10 or 1 x 12 oak, will a piece with a span of 57 inches eventually sag in the middle without stiffeners added? The shelf will only hold pictures.. nothing heavy..

[pushkins]

The simple answer is yes, over time it will sag. The easy fix is to add a piece of the same material on the front and rear edges of the shelf, glue and finish nail it to the shelf then sand and finish it all the same.

[JUNEBUG 88]

I built utility shelves from red oak planks from pallets (FREE). They averaged 1x8-1x14 again FREE. The span is 8 ft and they are holding well over 200#-400# each and have sagged only a couple of inches since I built them 10 years ago. For finished work I would personally add a brace to them in the middle.
I also built car/truck ramps out of the wood using pieces the size of 1x10's and approx 1' long supported by 2 pieces of 1x14's about 4' long cut at an angle. The small pieces were screwed between the longer boards to form a ramp. It supports the front of my pickup no problem.