Planning reference
Why “two per floor” is only a starting point
Government premises guides state that one water-based extinguisher for approximately every 200 m², with a minimum of two per floor, will normally be adequate for typical Class A risk. They also recognise that a very small self-contained premises below 90 m² may, after assessment, use one suitable multi-purpose unit.
Those examples do not override the current code of practice, product ratings or the FRA. Irregular layouts, separated areas and higher hazards can require more equipment.
Quantity factors
Five things determine the real number
The competent specification combines the general Class A provision with separately located protection for special hazards.
Floor area and ratings
Use tested fire ratings rather than capacity alone.
Storeys and compartments
Equipment must remain accessible on each relevant level and route.
Travel and layout
Long corridors, separated units and locked areas affect reachability.
Special hazards
Cooking, liquids, gases, electrical rooms, metals and batteries need distinct decisions.
People and environment
Weight, disability, public access, contamination and visibility affect selection.
Siting
The correct number in the wrong locations still fails
General extinguishers are commonly positioned on escape routes near exits, while special-hazard units should be close enough to the hazard to be useful but placed so the user is not drawn towards danger. Government guides commonly use 30 metres as an indicative maximum travel distance.
Units should be conspicuous, signed where necessary, protected from damage and mounted at a usable height. Security measures must not prevent prompt access.
Compare quotations
Ask the supplier to show the calculation
A quotation should schedule each unit by location, agent, capacity and fire rating and explain the premises assumptions. It should separate survey, supply, commissioning, signage, disposal and ongoing servicing.
Revisit the provision after changes in layout, process, stock, occupancy or the FRA.
- Floor plans and use of each area supplied
- Class A rating calculation stated
- Special hazards listed separately
- Travel distances and escape routes considered
- Every proposed unit identified by rating and location
- Commissioning, maintenance and disposal included