Technical Statement
Product Description
Scope of use
As the primary function of the rainwater system is to efficiently disperse rainwater from the roof to the stormwater drain network, it is imperative to ensure the correct sizing and number of downpipes are used in conjunction with the chosen gutter profile. Where the gutter capacity is greater than the downpipe capacity then the downpipe capacity will determine the number of downpipes required. Conversely where the downpipe capacity is greater than the gutter capacity then the gutter capacity will determine the number of downpipes required.
Gutter and downpipe systems must be designed and installed to ensure overflows are to the outside of the structure.
Fascia is used as a base to attach the gutters to, or as a cover to hide the fixing space between the roof, eaves and wall.
New Zealand Building Code (NZBC)
The product will, if employed in accordance with the supplier's installation and maintenance requirements, assist with meeting the following provisions of the building code:
- Clause B2 Durability: Performance B2.3.1(c)
Depending on product material and environments:
Paint surfaces warranty on Rainwater products up to 10 years
Perforation warranty— gutters up to 10 years, fascia up to 15 years
- Clause E1 Surface water: Performance E1.3.2
E1.3.2
See individual profile information for water carrying capacities
- Clause E2 External moisture: Performance E2.3.1
· E2.3.1
Standard design details can be accessed from the web: www.stratco.co.nz/nz/roofing/gutters/
- Clause G12 Water supplies: Performance G12.3.2, G12.3.2(a), G12.3.2(b), G12.3.2(c)
Colorsteel and Colorcote tested in accordance with AS/NZS 4020:2005 passed the requirements for products in contact with drinking water.
Evidence
The product meets the requirements set out in the following documents, or relevant parts of cited standards within the documents:
Zinc/alum coated steel substrate conforms with AS 1397:2013.
Pre-painted metals available provide solutions for different environments including various metals, metallic coatings, paint systems and paint thickness. The paint coatings are manufactured in accordance with AS/NZS 2728:2013.
Supporting evidence
The product has and can make available the following additional evidence to support the above statements:
Use in Service History
Test data is available for coil supplied by NZ Steel (COLORSTEEL) and Pacific Coilcoaters (COLORCOTE). Supporting evidence provided where requested will apply to the product substrate supplied for the specific project.
Both Colorsteel and Colorcote have past history of in-service use of metal long run roof and wall cladding within New Zealand.
Product Criteria
Design requirements
Roof area to be drained.
Local average rainfall intensity (ARI) for building location.
Capacity and fall of gutter. Gutters must be installed to a minimum fall to the downpipe of 1:500 (2mm per metre).
Capacity and number of downpipes required. If the gutter capacity is greater than the downpipe capacity the downpipe capacity will determine the number of downpipes required. Conversely where the downpipe capacity is greater than the gutter capacity then the gutter capacity will determine the number of downpipes required.
Gutter and downpipe systems must be designed and installed to ensure overflows are to the outside of the structure.
The design and use of rainheads where applicable.
In snow regions for building location, the addition of snow straps may be required for gutter systems.
Collection of drinking water.
Run off from, dissimilar metals such as stainless steel and copper should be avoided with any coated or uncoated roofing products
Installation requirements
Roof overhang into the gutter is to be a minimum 50mm.
Gutters must be installed to a minimum fall to the downpipe of 1:500 (2mm per metre). Good practice is to increase this to 1:200 (5mm per metre).
The back face of gutters must be lower than the fascia or cladding and have a gap between the fascia and gutter to allow overflow water to drain. This gap is normally provided for by the gutter bracket however if it is not then the gutter should be spaced off the fascia to ensure there is a 6mm gap.
Eaves flashings must be installed where required.
Set out and drop heights for wall & soffit framing to be allowed for with Stratco metal fascia—Refer www.stratco.co.nz/siteassets/pdfs/185-continuous-fascia-set-out.pdf
Maintenance requirements
More regular maintenance is required on the areas that are not naturally washed by rain. These areas include steel fascias and gutters.
Depending on environment, gutters should be cleaned out:
Moderate — six monthly
Severe — three monthly
Very severe — monthly
Cleaning should also be more often where there are high levels of leaf fall and/or dust.
Wash areas that are not naturally cleaned by rain with fresh, clean water. If washing with clean water does not completely clean the surface, a mild solution of detergent should be added to the water and applied with a soft bristled nylon brush or by water blasting at pressures of no more than 20MPa. Rinse the painted surface thoroughly with clean water. Never use abrasive or solvent based cleaners such as turps, petrol or kerosene.
Environmental
Stratco has Toitu Enviromark Gold Certification. Stratco sites recycle all steel and aluminium scrap and offcuts which can then be remelted for use in other steel products.
Steel and aluminium are infinitely recyclable so at the end of its useful life the product can be recycled and remelted for other products.
Relationships
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Environmental Choice New Zealand |
Building Product Information Requirements
Manufacturer
Legal Trading Name:
Stratco
Business Email:
technical@stratco.co.nz
Company Website:
www.stratco.co.nz
Contact Number/s:
03 3389063
0800 787282
Product Identifier
QUAD GUTTER, 1/4 ROUND GUTTER, EDGE GUTTER, VC GUTTER, 1/2 ROUND GUTTER, SMOOTHLINE GUTTER CONTINUOUS FASCIA DOWNPIPES
Warnings
This product has no warnings associated with it.
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Date last validated:
17 June 2024 |
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Date last updated:
17 June 2024 |