Metal Cladding Building Codes & Rules

- Metal cladding requires precision. Learn how to manage drainage, fixings, and material compatibility to prevent costly mistakes and ensure long-term durability.

AS 4200.2:2017, 3.7.1 (a) (i)

≥ 150^{AS 4200.2:2017, 3.7.1 (a) (i)}

Industry Recommendation

10^{Industry Recommendation}

Industry Recommendation

100^{Industry Recommendation}

AS 1562.1:2018, 4.4

Fixings^{AS 1562.1:2018, 4.4}

Only use fixings that are recommended in the system design
Place fixings in the middle of supports
If hook bolts, near the top edge
If assembly includes washers, must be
Compatible with sheeting
Able to withstand wind loads
Ensure sheets won't be deformed when piercing holes for fasteners
Manufacturer tools may be provided for safe hole punching

Insulation

Open Horizontal Profile Cladding

Manufacturer's Requirement

Metal Cladding Location in Various Environments^{Manufacturer's Requirement}

Install 100 to 200m away from
Breaking waves, to prevent exposure to corrosive salt spray
Sources of industrial emissions, where air quality is generally improved

Internal Corner Flashing

Ground Flashing

Fully

Sarked

Manufacturer's Recommendation

Spacing to follow

Cladding Requirement^{Manufacturer's Recommendation}

Head

Flashing

Cavity

Closer

Framing Overview (Light Steel)

External Corner Flashing

Sill

Flashing

Jamb

Flashing

Metal Stud

Batten

Industry Recommendation

110^{Industry Recommendation}

NCC 2022 Vol 2, H1D7 (5)

AS 1562.1:2018, 4.8

Flashings

Metal Wall Cladding to AS 1562.1^{NCC 2022 Vol 2, H1D7 (5)}
Flashing to Windows, Doors & Openings to Metal Wall Cladding Manufacturers Requirements^{AS 1562.1:2018, 4.8}

Manufacturer's Requirement

Top Plate Moisture Barrier^{Manufacturer's Requirement}

Separates dissimilar Roof / Wall framing materials (eg when installing a Timber Roof Frame onto Light Steel Frame Walls
Not required for Metal Wall to Metal Roof Frames

Finished Ground

≥ 100mm to well-drained areas^[1]
≥ 50mm to impermeable areas^[2]
≥ 150mm to any other areas^[3]
≥ 50mm extension below the bearer^[4]

Cladding to Ground CLEARANCE

NCC 2022 V2

All Building Classes

NCC 2022 7.5.7 [2019 3.5.4.7]

May 2023

NCC 2022 HP, 7.5.7 (1)

NCC 2022 HP, 7.5.7 (2)

Clearance^{NCC 2022 HP, 7.5.7 (1)}
≥ 100mm in well-drained areas
Low rainfall intensity areas or sandy
≥ 50mm above impermeable areas that slope away from the building
≥ 150mm in any other case
Extension^{NCC 2022 HP, 7.5.7 (2)}
≥ 50mm wall cladding extension below the bearer or lowest horizontal part of the suspended floor framing

NCC 2022 HP, 7.5.7 (1) (a)

NCC 2022 HP, 7.5.7 (1) (b)

NCC 2022 HP, 7.5.7 (1) (c)

NCC 2022 HP, 7.5.7 (2)

≥ 100mm to well-drained areas^{NCC 2022 HP, 7.5.7 (1) (a)}
≥ 50mm to impermeable areas^{NCC 2022 HP, 7.5.7 (1) (b)}
≥ 150mm to any other areas^{NCC 2022 HP, 7.5.7 (1) (c)}
≥ 50mm extension below the bearer^{NCC 2022 HP, 7.5.7 (2)}

Framing Overview (Timber)

Industry Recommendation

Insulating Metal Pipes in Cold Climate^{Industry Recommendation}

Reduces heat loss
2° to 4°F increase in water temperature, as compared to uninsulated pipes
Allows for lower temperature setting
Mitigates risk of frozen pipes
Some options may be to utilize
Pipe sleeve
Heat tape
Heat cable

NCC 2022 HP, 10.8.1

Warm Weather Vapour Barrier on External Walls^{NCC 2022 HP, 10.8.1}

≥ 0.143 µg/N.s vapour permeance in Climate Zones 4 & 5
To comply with AS 4200.1 & AS 4200.2

Under-Sill

Flashing

Manufacturer's Requirement

Bottom Plate Moisture Barrier^{Manufacturer's Requirement}

Install an impermeable membrane beneath perimeter bottom plates which are fixed on concrete slabs
Extend to weatherside flange
Pre-made adhesive membranes
Preferred way of protection
≥ 10mm extension on both sides of bottom plate
For other types of membranes
Compliant to AS 2870 or AS/NZS 2904, or
CodeMark Certified

Manufacturer's Recommendation

Open Profile Metal Cladding^{Manufacturer's Recommendation}

Has open ribs or gaps that let air pass through
Corrugated & trapezoidal profiles
Vertical
Attach directly to wall frame
Allows air to flow & water to drain
Horizontal
Install on vertical battens to allow ventilation & drainage behind the cladding

Provide insulation between cladding & steel frame to reduce heat transfer

Closed Vertical Profile Cladding

Manufacturer's Recommendation

Closed Profile Metal Cladding ^{Manufacturer's Recommendation}

Has limited airflow underneath
Standing Seam profile
Horizontal & Vertical
Install battens for airflow & drainage
For vertical cladding, install packers to keep assembly secure & dry

Open Horizontal Profile Cladding

Open Vertical Profile Cladding

NCC 2022 HP, 10.8.1

Cold Weather Vapour Barrier on External Walls^{NCC 2022 HP, 10.8.1}

≥ 1.14 µg/N.s vapour permeance in Climate Zones 6, 7 & 8
To Comply with AS 4200.1 & AS 4200.2

Closed Horizontal

Profile Cladding

Sarking

Batten Packing

Overlap

Thermal Breaks

R ≥ 0.2 for thermal breaks to prevent thermal bridging^[1]
Install insulating strips between metal frames & cladding^[2]

Metal-framed Wall Thermal Break Requirement RULES

NCC 2022 V1

Class 1 & 10a

NCC 2022 HP Part 13.2.5 [2019: 3.12.1.4]

May 2023

NCC 2022 HP, 13.2.5 (5)

NCC 2022 HP, 13.2.5 (5) (a)

NCC 2022 HP, 13.2.5 (5) (b)

NCC 2022 HP, 13.2.5 (5)

NCC 2022 HP, 13.2.5 (6)

Exterior Metal-framed Walls requiring Thermal Break^{NCC 2022 HP, 13.2.5 (5)}
No Wall Lining^{NCC 2022 HP, 13.2.5 (5) (a)}
Linings directly attached to the Metal Frame^{NCC 2022 HP, 13.2.5 (5) (b)}
Cladding of Weatherboards, Fibre-cement & the like^{NCC 2022 HP, 13.2.5 (5) (b)}
R ≥ 0.2 materials installed between Cladding & Metal Frame^{NCC 2022 HP, 13.2.5 (5)}
Walls constructed using Insulated Sandwich Panels are exempted^{NCC 2022 HP, 13.2.5 (6)}

Metal-Framed Wall Thermal Bridging Methods

NCC 2022 V3

Class 1 & 10a

NCC 2022 Part 13.2.5 [2019: 3.12.1.4]

May 2023

NCC 2022 HP, 13.2.5 (4) (b)

NCC 2022 HP, 13.2.5 (4)

Thermal Bridging in a Metal-framed wall to be achieved according to type of construction^{NCC 2022 HP, 13.2.5 (4) (b)}
Concrete Block Walls with Internal Lining
Lightweight Construction
Masonry Veneer, or
Choose one of the pre-defined solutions for External Wall for Thermal Bridging Mitigation^{NCC 2022 HP, 13.2.5 (4)}

NCC 2022 HP, 13.2.5 (5)

Industry Recommendation

R ≥ 0.2 for thermal breaks to prevent thermal bridging^{NCC 2022 HP, 13.2.5 (5)}
Install insulating strips between metal frames & cladding^{Industry Recommendation}