This 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 conforming to the performance requirements
specified in BS EN 12056-3:2003, 6.2. 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.
BS 8490:2007 Referenced Document
BS EN 752 Drain and sewer systems outside buildings - Sewer system management
BS 8490:2007 history
2007BS 8490:2007 Guide to siphonic roof drainage systems