Ensuring best practice across the UK's siphonic drainage sector
Our mission statement:
To research, set standards and disseminate best practice in UK siphonic drainage, from design to installation.
Siphonic drainage was first introduced in the 1960’s in Scandinavia and since then has been used widely across Europe, including the UK, in the Far East, Australasia, South Africa and the USA. Many large industrial, commercial and retail buildings are now fitted with siphonic drainage, which has clear advantages over gravity drainage.
SRDA recognises and is committed to the adoption of the Trade Association Forum ‘Best Practice Guide 2006’ wherever feasible.
SRDA - the new British Standard is ‘live’
“Slower than normal – but we have arrived” was the wry comment from John Purser, Panel Chairman of the group who have completely updated the guidance document for Siphonic Roof Drainage, now British Standard BS8490:2025.
The Standard will be of interest to a far wider group than just siphonic installation contractors. Roofing and cladding designers need it to be aware of correct gutter sizing and civils designers for the specific requirements in the underground drainage. Facilities managers and building owners will need it to make sure regular maintenance is adhered to.
About the SRDA
The Siphonic Roof Drainage Association (SRDA) was set up in 2004 to promote a wider understanding of the principles of siphonic drainage, to encourage best practice by suppliers and installers and to provide a recognised platform for specifiers. Members are subject to an independent third-party technical audit every three years, comprising a site inspection and a check of design compliance with BS8490.
Full members of the association:
- Must comply with the SRDA Constitution and Criteria
- Be a UK-registered company
- Have access to independently accredited software for drainage design to BS8490
- Have an independently accredited siphonic outlet
- Must ensure that all pipework and clamping systems to be in compliance with SRDA standards
- Employee registered installers working to British Standard and SRDA-approved methods
By using a member of the SRDA, a specifier can have confidence that the company has the tools and experience to do the job properly. If you cannot specify SRDA, then its rules can be used to set a standard.
SRDA services
The Siphonic Roof Drainage Association offers a range of support:
- Free technical advice via email or telephone
- Free technical document downloads