NCC 2019 Volume Three
Tas Section F Stormwater drainage systems

Tas Section F Stormwater drainage systems

Tas Part F1 Roof drainage systems

Tas Introduction

This Part sets out the requirements for the design, construction, installation, replacement, repair, alteration and maintenance of any part of a roof drainage system.

Explanatory information:

Explanatory information:

Explanatory information:

Objective

Tas FO1

The Objective of this Part is to—

  1. safeguard people from illness, injury or loss (including loss of amenity) due to the failure of a roof drainage installation; and
  2. ensure that a roof drainage installation is adequate; and
  3. conserve water and energy; and
  4. safeguard the environment; and
  5. safeguard public and private infrastructure; and
  6. 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).

Functional statements

Tas FF1.1

Buildings are to be provided with a roof drainage installation constructed to provide protection for people, property and the environment from the adverse effects of stormwater.

Tas FP1.1 Roof drainage systems

(1)

A roof drainage system must have capacity to transfer an average recurrence interval of rainfall generated from a storm.

(2)

The average recurrence interval of rainfall in (1) must be appropriate to the following:

(a)

The importance of the building

(b)

The severity of potential damage to the property

(c)

The severity of potential damage to property, loss of amenity, illness, or injury that would result from the failure of the system.

Tas FP1.2 Overview

(1)

A roof drainage system must provide an overflow device to transfer stormwater flows generated by extreme rainfall events.

Tas FP1.3 Watertightness

(1)

All internal roof drainage components must be watertight.

Tas FP1.4 Design, construction and installation

(1)

A roof drainage system must ensure the following—

(a)

Stormwater is transferred to a point of connection.

(b)

Access for maintenance and clearing blockages.

(2)

A roof drainage installation must avoid the following—

(d)

Foul air and gases accumulating in the roof drainage system

(c)

Loss to buildings and property amenity due to blockages and uncontrolled discharge.

Verification Methods

There are no Verification Methods in this Part.

Deemed-to-Satisfy Provisions

Tas F1.1 Application

(1)

Performance RequirementsTas FP1.1 to Tas FP1.4 are satisfied by complying with Tas F1.2.

Tas F1.2 General requirements

(1)

The design, construction, installation, replacement, repair, alteration and maintenance of a roof drainage system must comply with—

(a)

AS/NZS 3500.3; or

(b)

the acceptable construction practice of Part 3.5.2 of the Building Code of Australia Volume Two.

Tas Part F2 Surface and subsurface drainage systems

Introduction

Explanatory information:

Explanatory information:

Objective

Tas FO2

The Objective of this Part is to—

  1. safeguard people from illness, injury or loss (including loss of amenity) due to the failure of a stormwater drainage installation; and
  2. ensure that a stormwater drainage installation is adequate; and
  3. conserve water and energy; and
  4. safeguard the environment; and
  5. safeguard public and private infrastructure; and
  6. ensure that a stormwaterdrainage installation is designed and is capable of being maintained so that throughout its serviceable life it will continue to satisfy Objectives (a) to (e).

Functional statements

Tas DF2.1

Buildings and their surroundings are to be provided with a surface drainage and subsurface drainage installation and be constructed in such a manner as to provide protection for people, property and the environment from the adverse effects of stormwater.

This Part sets out the requirements for the design, construction, installation, replacement repair, alteration and maintenance of any part of a surface drainage system to the point of connection.

Performance Requirements

Tas FP2.1 Surface drainage systems

(1)

A surface drainage system must have capacity to transfer an average recurrence interval of rainfall generated from a storm.

(2)

The average recurrence interval for rainfall in Tas FP2.1(1) must be appropriate to the following:

(a)

The importance of the building

(b)

The severity of potential damage to property, loss of amenity, illness or injury that would result from the failure of the system.

Tas FP2.2 Sub-surface drainage

(1)

A subsoil drainage system must remove excess groundwater and reduce soil moisture levels to prevent loss by changing soil moisture conditions.

Tas FP2.3 Design, construction and installation

(1)

A surface drainage installation must avoid the following:

(b)

Damage from root penetration, superimposed loads or ground movement.

(c)

Entry of sewage and/or liquid trade waste.

(d)

Entry of stormwater into a sanitary drainage.

(e)

Damage to the Network Utility Operator's drainage system

(f)

Foul air and gases accumulating in the stormwater system.

(g)

Loss to buildings or property.

(2)

A surface drainage installation must ensure the following:

(a)

Access for maintenance and clearing blockages.

(b)

Stormwater is transferred to a point of connection.

Verification Methods

There are no Verification Methods in this Part.

Deemed-to-Satisfy

Tas F2.1 Application

(1)

Performance RequirementsTas FP2.1 to Tas FP2.3 are satisfied by complying with Tas F2.2.

Tas F2.2 General Requirements

(1)

The design, construction, installation, replacement, repair, alteration and maintenance of a surface and subsurface drainage system must comply with—

(a)

AS/NZS 3500.3; or

(b)

the acceptable construction practice of Part 3.1.2 of the Building Code of Australia Volume Two.