Scope
This section covers
- Gutters
- Downpipes
- Metal Fascia
- Ridge flashing
- Valley flashing
- General flashing
- Barge gutter
- Edge roll
- Barge Angle
- Barge
- Roof plumbing fixtures
- Gutter protection.
This specification should be read in conjunction with the specification for Site Drainage and Plumbing
?, which covers other elements necessary for the management of stormwater.
Relevant Standards
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- AS 1273 Unplasticised PVC (UPVC) downpipe and fittings for rainwater
- AS 2179.1 Specifications for rainwater goods, accessories and fasteners - Metal shape or sheet rainwater goods, metal accessories and fasteners
- AS 2179.2 Specifications for rainwater goods, accessories and fasteners – PVC rainwater goods and accessories
- AS 3500.3 National Plumbing and Drainage - Stormwater drainage
- AS 3959 Construction of buildings in bushfire prone areas
- AS/NZS 4994.2 Temporary roof edge protection for housing and residential buildings – installation and dismantling.
Commencement
Work shall commence as soon as practical after, but not before,
(a) The Builder has issued:
- a written order
- the relevant contract drawings, specifications and schedule of work
- written approval of any details provided by the Contractor
(b) The roof cladding is constructed and approved.
Construction
Stormwater drainage shall comply with the Drawings, Building Regulations and relevant Standard (AS/NZS 3500.3, except that for domestic installations, AS/NZS 3500.5 shall be used.)
Bushfire Prone Areas
For construction in areas that are prone to bushfire, all materials and construction shall comply with Drawings, Building Regulations and relevant Standard (AS 3959).
Materials
Inspections and Tests
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All new work shall remain open until it has been inspected and approved by the Builder.
The following inspections shall be performed.
| Item or Product | Inspection Required | Accept Criteria | Hold / Witness
| | Drawings & Specifications | Inspect controlled documents | Controlled copy of latest issue on site | Hold
| | Fascia | Visual | As specified
Adequate support | Witness
| | Flashing | Visual
Hose roof | As specified
No leaks | Witness
| | Gutters | Visual
Hose roof | As specified
No leaks
Specified fall
Adequate support | Witness
| | RWDPs | Visual
Hose roof | As specified
No leaks
Adequate support | Witness
| | Leaf screens | Visual | As specified
No gaps | Witness |
|
Potential Problems and Solutions
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Safety on Roofs
The contractor should provide safety rails where required by the workplace health and safety authority, if they are not already in place.
Rainwater Down Pipes
Rainwater downpipes must drain positively to the corresponding stormwater pipes. Check the falls and locations of proposed stormwater pipes before finalising the location of rainwater downpipes.
Leakage at Flashings
To avoid leakage at flashings, ensure that clear details are provided to the roof plumber. Check for leakage by hosing the roof before the fixing of the ceiling.
Flashing and RWDP Colours
Some of the “standard” colours are less common than others, and their availability may be limited, thus causing potential delays in the job. Always check availability before committing to the proposed colour scheme.
Leaf Screens
In areas where trees can shed leaves on the roof, it is becoming common to install leaf screen over eaves gutters and valleys. This will reduce the incidence of blocked down pipes and reduce the risk of fire damage due to blown embers. In bushfire-prone areas, leaf screens must have a Flammability index not more than 5.
Consideration should be given to the following questions.
- Are the leaf screens required to be fire-resistant?
- Is the material metal or plastic?
- What is its Flammability Index?
- How are the screens fixed to the gutter?
- How are the screens fixed to the roof? (i.e. Are they fixed under the tiles or on top?)
