What sits behind your cladding matters just as much as what you can see.
Sarking and moisture barriers are the invisible layer between your cladding system and your building’s structural frame. Installed correctly, they control moisture movement, manage condensation, and — in many cases — provide a secondary line of defence against water ingress if the outer cladding is ever compromised.
In cladding replacement projects, sarking installation isn’t optional. It’s a requirement under the NCC for most building types and climate zones in NSW — and a specification requirement under most cladding system warranties.
At Atomic Projects, we treat sarking and moisture barrier installation as a precision activity, not a cursory wrap-and-move-on task. The performance of the entire facade system depends on getting it right.
1. Types of Products We Install
- Reflective sarking (foil-faced) — moisture barrier plus radiant heat control; specified under NCC Section J for thermal performance in most Sydney applications
- Breather membranes (vapour-permeable) — allows moisture vapour to escape the wall cavity while blocking liquid water ingress
- Composite systems — combination products providing both functions; increasingly specified for high-performance facade systems
2. Installation Process
- Substrate verified dry and clean before membrane installation
- Sarking installed lap-over-lap per manufacturer’s minimum overlap requirements
- All laps taped with compatible tape — no untaped joins
- Penetrations (pipes, fixings, service points) dressed with peel-and-stick flashing tape
- Cavity barriers installed at fire compartment boundaries before sarking proceeds over them
- ITP hold point: sarking layer inspected and signed off before panels are installed
3. Fire Compliance Coordination
Sarking installation must be coordinated with cavity fire barrier placement. Where the facade system includes a ventilated cavity, the fire engineer specifies the type and location of cavity barriers at each floor level or fire compartment boundary. We install the cavity barriers first, then install sarking to the top of each barrier — ensuring no continuous pathway exists through the cavity.
4. Why Atomic Projects
Our sarking installation doesn’t just tick a compliance box — it forms the protective backbone of your entire facade system.
We make sure it’s installed right, tight, and ready to perform.
Frequently Asked Questions
Is sarking required under the NCC for all cladding replacement projects?
Sarking requirements under the NCC depend on the building’s climate zone, construction type, and facade system specification. In most cladding replacement projects on Class 2 residential buildings in Sydney, a reflective sarking or breather membrane is specified — both for thermal performance and moisture control. The fire engineer and facade system manufacturer’s guidelines also drive the specification.
What’s the difference between reflective sarking and a breather membrane?
Reflective sarking (typically foil-faced) provides both a moisture barrier and a radiant heat barrier, reducing summer heat gain. A breather membrane (vapour-permeable) allows moisture vapour to escape from the wall cavity while blocking liquid water from entering. In some systems, a composite product performs both functions — product selection depends on cavity ventilation strategy, climate zone, and fire engineer requirements.
How does sarking interact with the fire compartmentation strategy?
Sarking and membranes must not bridge fire compartment boundaries without correctly specified cavity fire barriers. Where the facade system includes ventilated cavities, the fire engineer will specify barrier locations. Our team is experienced in coordinating sarking installation with cavity barrier placement to satisfy both waterproofing and fire performance simultaneously.
What happens if the sarking is damaged during panel installation?
Any damage to sarking or membranes during installation must be repaired before panels are permanently fixed — this is a mandatory hold point in our ITP. Installers are trained to handle membranes carefully, and our site supervisor inspects each section before panel installation proceeds. All repairs are documented with photos in the QA records.
Can you install sarking as a standalone upgrade without replacing the cladding panels?
In limited circumstances, yes — particularly where panel removal and reinstatement is feasible without full replacement. We recommend a full programme assessment first, as the economics of reinstating original (often non-compliant) panels rarely make sense. Where panels are compliant and sarking has simply failed, targeted panel removal and sarking upgrade is a legitimate scope we can price and deliver.
