Logistics and distribution centres

What makes a logistics building different

Modern distribution and fulfilment centres are larger, taller and more intensively used than traditional warehouses. Footprints of tens of thousands of square metres, clear heights for high-bay racking, dozens of dock doors and fast construction schedules are normal. Pre-engineered steel suits these buildings because the repetitive grid allows frames, purlins and cladding to be standardised and fabricated in volume, and erection can proceed in several zones at once. Many developers build speculative logistics boxes to a market-standard specification so the building can be leased to different occupiers.

Typical specification

Wider grids require longer purlins or joists and heavier frames, so the grid is a balance between operational flexibility and steel weight. Multi-span frames with interior columns at 20–25 m spacing are usually more economical than very long clear spans – see multi-span buildings.

Special requirements

• Fire protection – high-piled storage commonly uses ESFR (early suppression fast response) sprinklers under NFPA 13 or FM Global Data Sheet 8-9 in the US, or the equivalent national standards elsewhere. ESFR systems are sensitive to roof height and obstructions, and their weight and bracing are added as collateral load on the purlins.
• Dock wall – framed openings for dock doors, girts and jambs designed for door wind loads, bumper and leveller pits, and a canopy to protect loading.
• Slab and racking – very flat floors (FM2 / defined flatness classes) for very narrow aisle trucks; slab by others but coordinated with the column base reactions.
• Daylight and energy – skylights at 3–5% of roof area are common; roofs are increasingly designed for photovoltaic arrays.
• Expansion – expandable endwalls and phased construction allow the centre to grow with demand.
• Office and amenity – two-storey office blocks or mezzanines at the front of the building, often in a lean-to.

Roof and envelope

On roofs well over 100 m long, thermal movement is significant. A standing seam roof with sliding clips lets the panels expand and contract without stressing fasteners, and long single-length panels avoid end laps. Walls typically combine precast or masonry dado panels with pre-painted steel sheeting or insulated panels above.

Programme is often the critical constraint for logistics developers, who need to hand over to a tenant on a fixed date. Fabrication of frames and roll forming of secondary members can run in parallel with earthworks and slab construction, and containers can be sequenced so that erection proceeds zone by zone while the slab is poured behind. Repetitive grids also simplify the procurement of anchor bolts, which are usually delivered first so that they can be cast into the foundations well before the steel arrives.

Dock doors, levellers and wind-rated openings

The dock wall is the busiest part of a logistics building and the part most exposed to impact and weather. Its components come from several specialist suppliers, so the building frame must be detailed around their data.

Because dozens of doors in one wall create a long series of framed openings, door wind ratings (for example ANSI/DASMA 108 in the US, EN 12424 classes in Europe or AS/NZS 4505 in Australia) and the enclosure classification of the building must be consistent. See doors and framed openings.

World Steel for logistics developers

World Steel supplies complete PEB packages – frames, secondary members, standing seam roofing, dock canopies and accessories – for logistics developers and contractors, fabricated in repeatable modules for fast export supply and erection. Typical clients are in the commercial and industrial sectors in markets such as the United States and Canada, where projects are designed to ASCE 7 or NBC requirements.