If you manage or own a multi-storey building, you’ve probably seen a cabinet labelled “Dry Riser Inlet” somewhere near the entrance.
But what exactly is a dry riser, and why is it so important for fire safety?
A dry riser is a vital piece of firefighting infrastructure found in taller buildings.
It’s a network of pipes that allows the fire and rescue service to pump water up to different floors without running hoses up stairwells—saving time and improving safety during a fire.
What Does a Dry Riser Do?
A dry riser is a vertical pipe system that runs up through a building. It has an inlet connection on the ground floor—usually in a secure cabinet on the exterior or inside the entrance—and outlets (known as landing valves) at designated floor levels, often on every floor above ground level.
During a fire, firefighters connect hoses to the ground-level inlet and pump water into the system.
They can then connect hoses to outlets on the affected floor, giving them immediate access to water without trailing hoses through the building.
The system is “dry” under normal conditions, meaning it is not filled with water until needed.
This prevents damage from leaks and avoids pressure issues in high-rise settings.
Where Are Dry Risers Required?
In the UK, dry risers are typically found in:
- Buildings over 18 metres tall but less than 60 metres
- Large buildings with complicated layouts where external firefighting access is difficult
- Multi-storey commercial buildings like offices, shopping centres, or warehouses
- Blocks of flats or apartments with limited hose access to upper floors
- Hospitals, car parks, or industrial units with basement levels
For buildings over 60 metres in height, a wet riser—which is permanently charged with pressurised water—is usually required instead.
What Standards Apply to Dry Risers?
Dry risers must be designed, installed, and maintained in accordance with British Standards:
- BS 9990:2015 – The key standard for non-automatic fire-fighting systems in buildings, including dry and wet risers. It covers installation, testing, and ongoing maintenance requirements.
- BS EN 14339 – Specifies technical details for dry riser equipment such as inlet breechings and landing valves.
- BS 5041 – This standard includes various parts covering landing valves, inlet breechings, and other components.
The standards define the appropriate materials, diameters, pressure ratings, flow rates, and spacing of outlets to ensure that systems are safe and effective for the fire service.
What Size Is a Dry Riser?
According to BS 9990, a dry riser typically consists of galvanised steel pipework with an internal diameter of 100mm (4 inches). This size ensures an adequate flow of water to upper floors during firefighting operations.
Landing valves are usually installed on every floor above 18 metres and must be located inside a secure fire-rated cabinet, clearly marked and easily accessible to fire crews.
The system also includes:
- Drain valves at the base to remove any water after use
- Air release valves at the top to prevent airlocks
- Isolation valves for testing and maintenance
Maintenance and Testing
Like all fire safety systems, dry risers must be regularly inspected and tested to ensure they’re operational in an emergency.
Under BS 9990:
- A visual inspection is required every 6 months to check valves, signage, cabinet condition, and accessibility.
- A pressure test using water should be carried out annually by a competent contractor to verify that the system can hold the required pressure and flow rate.
If you’re a building owner, facilities manager, or responsible person under the Regulatory Reform (Fire Safety) Order 2005, it’s your duty to ensure that these inspections are carried out and recorded.
Let ESI Help You Stay Compliant
At ESI: Electrical Safety Inspections, we support landlords, property managers, and commercial clients across Farnborough, Camberley, Reading, Guildford, and throughout Hampshire, Surrey, and Berkshire with all aspects of fire safety compliance.
We can:
- Carry out dry riser inspections and annual pressure testing
- Provide remedial repairs or replacement of faulty valves and equipment
- Support your wider fire risk assessment and building safety responsibilities
If you’re unsure whether your building needs a dry riser, or when yours was last tested, get in touch with the team at ESI. We’ll give you clear advice and help ensure your system meets all the latest British Standards and legal requirements.
