Why Your Warehouse Stores Less Than the Building Suggests
Direct answer: Usable clear height is the distance from finished floor level to the lowest obstruction — sprinkler heads, lighting, ductwork or roof purlins — not the building's eaves height. Racking height is then set from usable clear height minus the sprinkler clearance the fire authority requires.
Start from clear height, not building height
Clear height is the lowest obstruction — usually sprinkler heads, lighting or roof beams — measured across the usable floor. Racking design starts there, and every level below must account for pallet height plus handling clearance.
A 150 mm handling gap on each beam level sounds small; across five levels it quietly removes a full pallet position from a planned layout.
The 75–150 mm rule
Most forklift specifications want roughly 75–150 mm of clearance above each pallet for lift, placement and withdrawal. Tighter clearances slow handling and raise damage rates; overly generous ones waste building height.
Confirm the actual figures with your forklift supplier before finalising beam elevations — mast tolerance varies by truck.
Sprinklers change the top level
Many codes require clearance below sprinkler heads, which caps the top beam level regardless of clear height. Check local fire requirements early; retrofitting the top level is expensive.
FAQ
What is clear height?
The vertical distance from floor to the lowest overhead obstruction (sprinklers, lights, joists) above the storage area — the true ceiling for racking.
How much clearance does a pallet need per level?
Commonly 75–150 mm above the tallest pallet load, depending on the forklift; confirm with your truck specification.
Can racking go right up to the sprinklers?
Usually no — fire regulations require a gap below sprinkler deflectors; the top level is set by that constraint.
How do I calculate storage capacity from clear height?
Subtract required clearances per level to get beam levels, multiply by bays per row and pallets per bay — always validate with a supplier layout drawing.
All figures above refer to standard product data sheets; final confirmation is subject to written quotation.