TGD H 2010 – 1.5.2.1 – SURFACE WATER DRAINAGE, Rainwater pipes

1.5.2.1 Rainwater pipes should discharge into a drain or gully but may discharge to another gutter or onto another surface if it is drained. Where a rainwater pipe discharges onto a lower roof or paved area, a pipe shoe should be fitted to divert water away from the building. Where rainwater from a roof with an effective area greater than 25 m2 discharges through a single downpipe onto a lower roof, a distributor pipe should be fitted to the shoe to ensure that the flow width at the receiving gutter is sufficient so that it does not over-top the gutter. Any rainwater pipe which discharges into a combined system should do so through a trap (see sub-section 1.2).

C:BCARTGDTGD hTGD%20H%202010TGD%20H%202010%20-%20SECTION%201%201.5.2.1-2.pdf