AS 1562.1 Design & Installation of Roof Cladding

Protect your property with compliant roofing—AS 1562.1 outlines how metal sheet cladding should be designed and installed for durability, safety, and structural performance. Whether you’re building new, renovating, or inspecting an existing roof, understanding this standard helps ensure long-term performance and compliance.

Table of Content

What is AS 1562.1?

AS 1562.1 (1992) is the Australian Standard that sets out the minimum requirements for designing and installing metal sheet roof and wall cladding. It is referenced in the Building Code of Australia (BCA) and applies to all Class 1 and Class 10 buildings, such as homes, sheds, garages, and carports.

This standard ensures:

  • Structural integrity under wind loads

  • Protection against corrosion and leaks

  • Compatibility of materials

  • Proper installation methods and safety

Who Uses This Standard?

  • Building inspectors – to check if existing structures meet national requirements

  • Roofing contractors – to follow correct installation practices

  • Engineers & designers – to calculate wind loads and support spans

  • Builders – to ensure compliant construction, especially in regulated areas

Key Components of AS 1562.1

Design Considerations

  • Roofing must resist local wind speeds (up to W41 in non-cyclonic areas)

  • Material strength and support span limits are clearly specified

  • Design must prevent water ingress, capillary action, and corrosion

Corrosion Protection

Different environments (inland, coastal, industrial) require different coatings:

  • Inland areas: Z275 or AZ150 galvanised steel

  • Coastal/industrial areas: AZ200 coatings, avoiding copper near galvanised steel

Material Compatibility

Avoid adverse chemical reactions:

  • No lead upstream of zinc-aluminium

  • No copper upstream of galvanised steel

  • Use compatible fixings, flashings, and downpipes

Sheet Installation Guidelines

  • Lay full-length sheets from ridge to eaves where possible

  • Follow correct lap lengths (150–200 mm, depending on slope)

  • Include anti-capillary breaks to prevent moisture buildup

  • Fasten according to specified spacing (rib pattern varies with profile type)

Flashing & Capping Requirements

  • Must be machine-folded, purpose-made, and chemically compatible

  • Flashings need to overlap and direct water flow correctly

  • Lead flashings are not allowed on potable water roofs or prepainted surfaces

Span Tables & Fixing Guide

AS 1562.1 includes detailed fixing spacing, roof pitch, and sheet profile limits, such as:

  • Corrugated (0.42 mm): max end span 950 mm, internal span 1200 mm

  • Trapezoidal (0.48 mm): end span 1800 mm, internal 2100 mm

  • Fastener frequency varies for concealed/pierced/corrugated systems

What Happens if You Don’t Comply?

Non-compliance with AS 1562.1 can lead to:

  • Roof leaks or premature failure

  • Insurance issues

  • Rejection at inspection stages

  • Health hazards if lead flashings contaminate drinking water catchments

Book an Inspection in Perth

Our inspectors are fully trained to assess timber-framed homes against AS 1684. Whether you’re building, buying, or renovating — book an inspection today to ensure your structure is safe, compliant, and built to last.

Roof Inspector Perth - Syed Ali

FAQ

1. Is AS 1562.1 mandatory for all roofs in Australia?
Yes, especially for Class 1 and 10 buildings. It's often enforced through the National Construction Code (NCC).

2. Can I use this standard for wall cladding too?
Yes. Although focused on roofing, it also applies to wall cladding with metal sheeting.

3. What types of metal are acceptable?
Galvanised, zinc/aluminium coated steel—must meet AS 1397 standards.

4. Do I need an engineer to apply AS 1562.1?
Not always, but engineering input is required for wind design loads, especially in higher-risk areas.

5. What happens if I mix incompatible materials?
It may cause galvanic corrosion, weakening your roof or walls over time.

6. Can I use lead flashing in modern roofs?
Not with zinc/aluminium coated or pre-painted steel, especially in potable water catchment systems.

7. Are alternative roofing systems allowed?
Yes, but they must meet the same performance requirements as AS 1562.1 through engineering documentation.

8. How often should flashings be fixed?
Depends on roof type—e.g., every rib for concealed fix, every 2nd/4th rib for pierced or corrugated.

9. Are there visual diagrams in the standard?
Yes, it contains diagrams for span spacing, side lapping, and acceptable flashing methods.

10. Where can I access the full standard?
The full document must be purchased via Standards Australia or viewed via authorised platforms like SAI Global.