Stacking and Storing Materials

A stack does not lean and give you a warning. It stands, and then it is on the floor, and whatever was against it goes with it.

The requirement

1926.250(a)(1): all materials stored in tiers shall be stacked, racked, blocked, interlocked or otherwise secured to prevent sliding, falling or collapse. 1910.176(b) says the same for general industry, adding that height is limited so stacks are stable.

Floor loading — the one people forget

1926.250(a)(2): stored material must not exceed the floor's safe load limit, and the employer must conspicuously post the limit in pounds per square foot in storage areas within buildings and structures.

Palletised block, tile, drywall or steel on an upper floor concentrates a very large load on a small area. Structures have come down under material that was going to be used the same day. If nobody can tell you the floor's limit, that is a question for the engineer, not a judgement call for the delivery driver.

Stacking

• Interlock the layers. Brick, block, bags and boxes get cross-tied every few courses instead of stacking in straight columns.
• Heaviest at the bottom, tapered as you go up.
• Keep it plumb, and pull from the top down — never from the bottom of a stack, and never from the middle to get "that one".
• Block round stock — pipe, conduit, drums, cable reels — with wedges, racks or chocks. Pipe rolls, and it rolls quietly.
• Bagged material stepped back every few tiers so the face does not slide.
• Not against a wall you are not sure about, and never against guardrails, formwork or a temporary partition.
• Away from edges, holes and openings, and back from a trench by at least the depth of it — 1926.651(j) keeps spoil and material back from an excavation edge for exactly this reason.

Around the stack

• Aisles clear and marked, wide enough for whatever moves through them — 1910.176(a).
• Nothing within three feet of a sprinkler head, and clear of exits, panels and extinguishers.
• Nothing blocking a fire door or an escape route, ever.
• Damaged pallets out of service. A cracked stringer is how a stack goes over on a forklift.
• Look up before you pull. What is above the item you want, and where does it go if the stack shifts?

And the boring one

Clean up the banding. Steel strapping cut off a bundle and left on the ground snaps up, catches boots, and slices hands. Cut it, coil it, bin it.