Standards and Links

BS 8490 (UK British Standard)

BS 8490 is the British Standard applies to roof drainage systems using circular-section pipes that operate under siphonic action. It does not apply to siphonic drainage systems using rectangular or trapezoidal section conduits for water conveyance.

It gives information and provides guidance on design parameters, installation, verification and maintenance needs of siphonic roof drainage systems. Guidance is also given on carrying out checks of designs, for the use of specifiers and regulatory authorities. Particular issues for site drainage systems that receive flows from siphonic roof drainage systems are also covered.

ASPE 45:2018 (USA Standard)

ASPE’s first published plumbing design standard, Siphonic Roof Drainage, will help plumbing engineers and designers design and specify code-approved siphonic roof drainage systems.

This is a comprehansive standard to help Engineers of Record to design and specify siphonic roof drainage systems to prime and operate full bore through proper pipe dimensioning and the use of siphonic roof drains.

The purpose of this consensus standard is to establish the minimum performance specifications for siphonic roof drainage systems.

This concensus standard provides designers, installers and code officials with a “standard of practice” for the proper application of siphonic roof drainage.

The standard also provides guidelines for the inspection and testing of siphonic roof drainage installations.

ASME A112.6.9 (USA Standard)

This Standard establishes minimum requirements and provides guidelines for the proper design, installation, examination, and testing of siphonic roof drains. It includes definitions of terms and parameters involved in the proper design of siphonic drainage systems. This Standard applies to roof drains designed, manufactured, and installed in piping systems that are intended to operate under depressurized siphonic conditions created by the connected piping system.

Unless noted otherwise in this Standard, the requirements and standards for roof drains specified in ASME/ANSI A112.6.4 do not apply to siphonic roof drains. This Standard does not apply to conventional roof drains covered under ASME/ANSI A112.6.4. It is not the intent of this Standard to specify that a drain of a given diameter must drain a minimum or maximum amount of water. It is the intent of this Standard to provide standardized test procedures to ensure that drain products are evaluated equally. This Standard does not dictate minimum flow or depth performance criteria for siphonic roof drains. Instead, it specifies standard test procedures to be performed on siphonic roof drain products to document their actual performance and physical limits. These data are to be made available in manufacturer literature for use by designers for selecting the drain product and entering performance characteristics into design calculations.

SS525 (Singapore)

Code of practice for drainage of roofs

Deals with the drainage of rainwater from roofs (including external walls) and recommends methods of designing gutters, gutter outlets and rainwater downpipes. It includes calculation of catchment areas and the required flow rate. Performance requirements for siphonic roof drainage are also outlined.

3500.3:2018 (Australia & New Zealand)

Sets out requirements for materials, design, installation and testing of roof drainage systems, surface drainage systems and subsoil drainage systems to a point of connection.