The (almost) best laid plans: A lumber rack story: During the
remodel of my shop (burned rent house), I dedicated one bedroom for
lumber storage. Built racks with 2X4s on edge, with vertical supports
about 3' apart. http://www.flickr.com/photos/4383614...in/photostream

No doubt the racks would support most of the lumber I have.....
including quite a few hurricane-downed trees I had milled. Under the
racks, on the floor, I stored small 8" -12" diameter logs (to be used
for stair construction, later). With the racks about 2/3 filled, some
of the floor joists, of the room, failed. I had to get under the
house, jack up the flooring, add pillars and more 4X6 beam support. I,
also, scabbed sleepers along the broken joists. It could have been
worse.

Sonny