TAS Part E3 Stormwater - Roof drainage systems
Introduction to this Part
This Part sets out the requirements for a roof drainage system.
Objectives
The objective of this part is to—
- safeguard people from illness, injury or loss (including loss of amenity) due to the failure of a roof drainage installation; and
- ensure that a roof drainage installation is adequate; and
- conserve water and energy; and
- safeguard the environment; and
- safeguard public and private infrastructure; and
- ensure that a roof drainage installation is designed and is capable of being maintained so that throughout its serviceable life it will continue to satisfy Objectives (a) to (e).
Objective
Functional Statements
Buildings are to be provided with roof drainage to provide protection to people, property and the environment from adverse effects of stormwater.
Functional statements
Performance Requirements
Roof drainage systems
A roof drainage system must provide an overflow device suitable for a 1% annual exceedance probability rainfall event.
Overflow
All internal roof drainage components must be watertight.
Watertightness
- stormwater is transferred to a Network Utility Operator's stormwater system or an approved disposal system; and
- appropriate access is provided for maintenance and clearing blockages.
Design, construction and installation
Deemed-to-Satisfy Provisions
Performance Requirements E3P1 to E3P4 are satisfied by complying with E3D2 and E3D3.
Application
A roof drainage system must comply with—
- AS/NZS 3500.3; or
- Housing Provisions 7.4
General requirements
Explanatory information
TAS Figure E3D3 provides an example of a suitable installation practice to meet the requirements of E3D3(3).
Roofing of liquid trade waste generation areas