Hall height, fire protection, and floor requirements in warehouses – what you should consider when planning

For the fire protection assessment, it is not the height of the building that is decisive, but the height of the stored goods, i.e., the upper edge of the stored material including pallets or containers. Requirements are derived from this:

• Automatic extinguishing systems
• Fire compartment sizes
• Smoke and heat extraction systems
• Organizational measures

Standard thresholds

Up to approx. 7.5 m storage height
In individual cases, organizational measures and structural fire compartments may be sufficient. This depends heavily on the stored goods, packaging, and insurer requirements.

From approx. 7.5 m storage height
Above this height, an automatic sprinkler system is almost always required in practice. Depending on the stored goods – the fire load is usually the decisive factor here – in-rack sprinklers may already be necessary in this area.

From approx. 9 m storage height
The requirements increase significantly. Rack sprinklers or specially designed ceiling sprinkler solutions become more common, often with increased extinguishing water quantities and additional structural requirements.

From approx. 12 m storage height
These are usually high-bay warehouses with a project-specific extinguishing concept. Standard solutions are rarely possible here.

The choice of insurer and the underlying guidelines (e.g., VdS CEA 4001 or FM Global Data Sheets) influence:

• Type and arrangement of sprinklers
• Required extinguishing water quantities
• Technical areas and water storage
• Permissible storage heights and storage types
• Aisle widths and sprinkler clearance areas

Early specification prevents subsequent redesigns in the layout.

Ceiling sprinklers vs. rack sprinklers

Ceiling sprinklers cover a large area, but are highly dependent on the stored goods, distance to building components, and potential spray obstructions. In dense or high racking systems, the flow of water to the lower levels can be significantly reduced by shielding.

Shelf sprinklers act directly on the shelf and are often the more effective solution for high or dense shelving systems – even at medium heights.

The requirements for escape and rescue routes depend on usage, occupancy, and the property-specific fire protection concept.

A distinction must be made between:

• manually operated storage areas with permanent staff presence
• automatically operated racking systems that are not accessed during normal operation

Automated racking systems are not usually permanent work areas. Access is usually only permitted for maintenance or service purposes under special safety conditions. The specific design of escape routes is carried out by the responsible specialist planners and authorities as part of the overall fire protection concept.

Smoke and heat extraction systems must be adapted to the height of the hall, its use, and the rack layout. Racks, platforms, and enclosures have a significant influence on smoke flow.

The following should be planned at an early stage:

• Location and size of smoke extraction openings
• Supply air ducting
• Possible smoke curtains
• Maintenance and service access

High point loads act on shelf supports. However, it is usually not the permissible floor pressure that is decisive, but rather the deformation of the floor under load.

Excessive deformation can lead to:

• System tolerances being exceeded
• Guidance systems changing their position
• Additional forces being introduced into the rack structure

Verification is carried out in an iterative process between the floor structural engineer and the rack structural engineer. Load distribution plates alone are often not sufficient to control local deformation behavior.

For large racking systems, the initial flatness of the floor is usually less critical than the deformation behavior. Local unevenness can be compensated for during assembly, for example by:

• Adjusted anchoring
• Underlayments under base plates
• Systematic leveling of the shelving structure

Within limited limits, such floor deviations can be compensated for by the shelving system using the above measures without impairing the functionality of the system.

An uncoated, load-bearing concrete surface is often advantageous for shelving systems. Additional coatings such as epoxy resin can impair the quality of anchors and underlays and make subsequent adjustments more difficult.

Coatings should therefore be planned specifically for traffic areas, not across entire racking systems.

In addition to structural and fire protection requirements, the following should be considered at an early stage:

• Sprinkler clearance areas
• Maintenance and service access
• Coordination of joint planning and support positions
• Insertion openings and lifting options
• Fire department access routes and water supply

Hall height, fire protection, and floor requirements are closely linked in terms of technical aspects when planning a warehouse. As storage heights increase, automatic extinguishing systems become the norm, fire compartments supplement the technology, and the focus shifts to the deformation behavior of the floor.

Considering these issues together at an early stage creates a solid foundation for the approval, construction, and safe operation of modern racking systems.