By Sydney Contracting Engineers (SCE Corp) · Information checked 6 October 2026
Cladding corrosion can involve the visible panel, a fixing, a flashing or a concealed support. A stain on the surface does not identify which component is deteriorating or establish the remaining capacity of the assembly. The investigation should locate the affected parts and explain the mechanism before a repair method is selected.
If panels, fixings or other façade elements may be loose, keep people clear of the affected area and arrange prompt competent assessment. Do not disturb suspect components to obtain a closer photograph. The responsible team must determine any access restrictions or temporary controls.
Map the extent and pattern of corrosion
Map affected elevations and note the height, orientation and location of staining or deterioration. Record whether it occurs around fasteners, cut edges, joints, ledges, penetrations or adjoining materials. Include dated photographs taken from a safe position and any history of leaks or earlier repairs.
A repeated pattern may help the investigation distinguish an isolated damaged coating from a wider compatibility, wetting or installation issue. It does not prove the cause. SCE’s cladding warning-sign guide covers the initial condition record and escalation questions.
Identify the components actually installed
Gather specifications, product records, drawings and previous inspection reports. Ask which parts are verified and which are only assumed. The visible panel material may be known while fastener grade, subframe coating or concealed flashing remains undocumented.
- Outer panel or board and its protective finish.
- Fasteners, brackets and washers.
- Subframe or supporting members.
- Flashings, trims and adjacent metalwork.
- Interfaces where water can collect or flow between materials.
Where access or opening-up is needed, define a safe investigation method and reinstatement scope. The sample locations should answer a stated question rather than being chosen only because they are convenient to reach.
Check moisture and material compatibility together
Ask the appointed team to consider exposure, coating condition, trapped moisture, drainage and material combinations. BlueScope’s technical bulletin explains that dissimilar-metal contact and runoff can create compatibility concerns. Those mechanisms need assessment against the actual installed components.
Rondo’s discussion of top-hat corrosion also highlights why concealed supports deserve attention. A surface coating repair cannot be assumed to restore a deteriorated support or fixing connection.
Require a defined repair boundary
The resulting scope should state which components remain, which require treatment and which require replacement. Ask what evidence supports each decision and whether the extent needs further investigation. Where structural performance is involved, the appropriately appointed engineer should define the required response.
A replacement fastener should not be selected solely because it looks more corrosion resistant. Confirm its compatibility, capacity, installation requirements and relationship to the retained assembly through the design and product requirements. Do not treat a generic online material table as the specification for the building.
Plan the work and its verification
Include access, removal, temporary support where required, occupied-area protection and weather management in the repair scope. State the inspection points before the affected work is concealed. Keep records identifying installed products, treatment areas, substitutions, inspections and any unresolved conditions.
At handover, explain maintenance requirements and how the owner can arrange future access. If some parts were not opened or assessed, state that limitation clearly. A photograph of a repainted panel should not be presented as evidence that every concealed component has been examined.
Connect investigation to delivery
SCE’s façade portfolio provides documented examples of replacement work, installation and quality records. SCE can deliver investigation, engineering, design, procurement and construction within the agreed appointment, with specialist and independent certification responsibilities defined for the project.
Request a Project Suitability Review with the location, safe photographs, available material records, inspection history and known access constraints.
Frequently asked questions
Does rust staining prove the cladding panel is corroding?
No. Staining may originate from a fixing, support or adjoining material. The investigation should identify the source and affected components.
Can corroded fixings simply be painted?
That cannot be decided from appearance alone. The team must establish the component’s condition, function and required repair or replacement response.
Should every fixing be replaced with stainless steel?
Do not make a blanket substitution. The selected fastener must suit the complete assembly, exposure, capacity and product requirements.
What should a corrosion repair handover include?
Identify treated and replaced components, product records, inspections, approved changes, maintenance requirements and any areas that were not assessed.