Dry riser
Dry risers are used to supply water within buildings for fire-fighting purposes. The provision of a built-in water distribution system means that fire fighters do not need to create their own distribution system in order to fight a fire and it avoids the breaching of fire compartments by running hose lines between them.
Dry risers do not contain water when they are not being used, but are charged with water by fire service pumping appliances when necessary. This is as opposed to wet risers, which are permanently charged with water.
Dry risers have an inlet connector at rescue service vehicle access level and landing valves at locations on each floor. Part B of the building regulations (Fire Safety) requires that fire mains are provided in buildings that are more than 18 m tall. In buildings less than 50m tall, fire mains can be either dry or wet risers, however, where a building extends to more than 50 m above the rescue service vehicle access level, wet risers are necessary as the pumping pressure required to charge the riser is higher than can be provided by a fire service appliance, and to ensure an immediate supply of water is available at high level.
Each inlet connector must be within 18 m of a fire service appliance access. Inlet connectors are typically contained in accessible, but secure enclosures on the external face of buildings and are identified as a ‘dry riser inlet’.
Dry risers themselves should be within fire-fighting shafts, and where necessary in protected escape stairs. Dry riser outlets, or landing valves, may be located in protected lobbies, stairs or enclosures where these are available.
At the top of dry-riser pipework an air valve is provided to allow air in the dry riser to escape when the riser is charged with water. There is often also a roof-level testing outlet.
Dry risers should be inspected and tested regularly to ensure equipment is functioning correctly and ready for use. Problems can be very serious in the event of a fire, and are typically caused by vandalism or theft, blockages or pipework failure or by connection failure or outlets being open.
NB Planning Gateway One - Glossary, published on the Planning Portal, defines a dry riser/dry rising main/dry fire main as: ‘A water supply pipe installed in a building for fire-fighting purposes, fitted with inlet connections at fire service access level and landing valves at specified points, which is normally dry but is capable of being charged with water usually by pumping from fire and rescue service appliances.’
[edit] Related articles on Designing Buildings
Featured articles and news
Design and construction industry podcasts
Professional development, practice, the pandemic, platforms and podcasts. Have we missed anything?
C20 Society; Buildings at Risk List 2025
10 more buildings published with updates on the past decade of buildings featured.
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation, closing 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
From project managers to rising stars, sustainability pioneers and more.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.