A facilities manager responsible for a twenty-storey commercial tower on the western edge of Melbourne’s CBD noticed water staining appearing on the ceiling of a tenancy on level fourteen after a run of driving winter rain. The tenant assumed a plumbing leak. The building’s plumber found nothing. It took a facade specialist working from rope access to identify the real cause: a failed gasket and a degraded structural silicone joint on the facade two levels above, allowing wind-driven rain to enter the facade cavity and track down inside the wall before emerging as a stain far from its source. The repair itself was modest. The investigation, the tenant disruption, and the remediation of the water-damaged ceiling and finishes were not. The episode is a familiar one to anyone who manages a glass-fronted high-rise, and it illustrates why curtain wall maintenance is one of the most consequential and least understood responsibilities in commercial facilities management.

A curtain wall is the non-structural external skin that hangs off the face of most modern high-rise buildings in Melbourne, a lightweight assembly of glass, aluminium framing and sealed joints that keeps weather out while carrying none of the building’s floor loads. It is elegant, it is ubiquitous across the CBD, Southbank and Docklands, and it is a system that depends entirely on the integrity of components that degrade over time. For facilities managers, property managers and owners corporations, understanding what maintaining these systems involves, how they fail, and how to structure an inspection and upkeep programme has become essential to protecting both the building fabric and the tenancies within it. This guide sets out the technical realities, the failure modes, the regulatory context and the procurement considerations that building professionals need to act on.

What a Curtain Wall Actually Is

Before a facilities manager can manage these systems effectively, it helps to understand what the system is and how it differs from the masonry and window assemblies of older buildings. A curtain wall is a continuous, self-supporting envelope that is fixed to the building structure at each floor level but carries no structural load beyond its own weight and the wind pressure acting on it. The system transfers that wind load back to the floor slabs through brackets and anchors, and it accommodates the building’s movement through carefully designed joints. This is a fundamentally different proposition from a punched window set into a load-bearing wall, and it demands a different maintenance mindset.

These systems fall into one of two broad construction types. Stick systems are assembled piece by piece on site, with vertical mullions and horizontal transoms installed as individual components and the glazing infilled between them. Unitised systems are prefabricated into storey-height panels in a factory and craned into place, interlocking with the panels around them. Melbourne’s high-rise stock includes both, and the distinction matters for maintenance because the location of the weatherproofing joints, the way water is managed within the system, and the access required to reach failed components all differ between them.

The glazing itself is held in place by one of several methods, and each carries its own maintenance implications. Captured systems retain the glass mechanically with pressure plates and gaskets. Structural silicone glazing bonds the glass to the framing with high-performance silicone, dispensing with visible framing on some or all edges to achieve a flush glass appearance. Because structural silicone is doing a load-bearing job in these systems, its condition is a genuine safety matter and a central focus of any competent maintenance regime. Understanding which system a building uses is the starting point for managing it, and it is one of the first things a specialist establishes when assessing a facade.

How Curtain Wall Systems Fail

Effective maintenance depends on understanding the ways these systems deteriorate, because failure is rarely sudden and is almost always cheaper to address early. The components that keep the envelope watertight and secure all have finite lives, and Melbourne’s climate accelerates the decline of several of them. Recognising the mechanisms allows a facilities manager to interpret an inspection report and prioritise remediation sensibly.

Sealant and Gasket Degradation

The most common failure is the loss of weatherproofing at the joints. Perimeter sealants, the weather seals between the facade and adjoining construction, and the gaskets that seal the glazing into the framing all degrade under ultraviolet exposure, thermal cycling and simple ageing. Melbourne’s strong summer ultraviolet and its wide daily temperature swings drive sealant hardening, cracking and eventual loss of adhesion. Once a seal fails, water finds the path, and because these systems are designed to manage some water within the system rather than exclude it absolutely, a failed seal can allow ingress that travels a considerable distance before it becomes visible inside the building. Sealant replacement is a core element of curtain wall maintenance and one of the highest-value interventions a building can undertake, because it prevents the far greater cost of water-damage remediation.

Structural Silicone Deterioration

In structural silicone glazed systems, the silicone bond is what holds the glass to the frame. Over decades, that bond can degrade through ultraviolet exposure at the edges, contamination, or original application defects that only manifest years later. Loss of structural silicone adhesion is a serious matter because it concerns the retention of glass at height. This is precisely why maintenance on structural silicone systems must include competent assessment of the silicone condition, and why this work sits at the intersection of glazing expertise and height safety rather than being a routine cleaning task.

Drainage Path Blockage

Curtain walls manage water through an internal drainage system, often described as pressure-equalised or rain-screen design, that collects any water penetrating the outer line and directs it back out through weep holes. When those weep holes and internal gutters become blocked with dirt, debris or building sealant applied during earlier repairs, the drainage path fails and water accumulates within the system. This is one of the more insidious failures because it is invisible from outside and often from inside until damage appears. Clearing and reinstating the drainage path is a maintenance task that a specialist will check as a matter of course, and it connects directly to the commercial facade repairs capability required to remediate a system where drainage has been compromised.

Corrosion and Coastal Exposure

The aluminium framing of the system is generally durable, but fixings, brackets and anchors within the system are vulnerable to corrosion, particularly on buildings in Melbourne’s bayside suburbs where salt-laden air accelerates the deterioration of metal components. Properties in Port Melbourne, St Kilda, Elwood and the wider bayside area contend with a corrosive atmosphere that acts continuously on concealed metal within the facade. Maintenance in these locations warrants closer attention to fixing condition, because the components that transfer wind load back to the structure must remain sound.

Glazing Seal and Unit Failure

Where the system incorporates double-glazed units, the edge seals of those units can fail, allowing moisture into the cavity between the panes and producing the fogging and condensation that signals a failed insulated glazing unit. This is a distinct failure from the facade’s own weather seals, though the two are often confused. Our detailed guidance on condensation between double-glazed windows sets out how insulated glazing units fail and when replacement is warranted, and it complements the broader curtain wall maintenance picture by addressing the glass units the system holds.

The Regulatory and Compliance Context

Facilities managers cannot treat this upkeep purely as a discretionary matter, because several regulatory obligations bear on the condition of a building’s external envelope. Understanding how they apply establishes curtain wall maintenance as a compliance responsibility rather than an optional cost.

The Occupational Health and Safety Act 2004 and the Occupational Health and Safety Regulations 2017 impose a duty on those who manage or control a workplace to ensure, so far as is reasonably practicable, that it is safe. A facade with deteriorating structural silicone, loosening fixings or a risk of falling glazing is a hazard that falls within this duty, and the reasonable-practicability standard effectively requires that a building manager know the condition of the facade. That knowledge comes only from inspection, which is why a structured curtain wall maintenance programme is the mechanism by which the duty is discharged. WorkSafe Victoria is the enforcing authority, and it does not accept ignorance of a facade’s condition as a defence.

The essential safety measures regime adds a further dimension. Where facade elements are captured as essential safety measures, or where the works required to maintain the facade themselves engage fire-safety or access systems, the annual essential safety measures report must reflect their condition. Since 1 July 2025, the Building and Plumbing Commission Victoria has assumed the building regulatory functions previously administered by the Victorian Building Authority, and facilities managers should ensure their compliance documentation references the current body. For owners corporations, the obligation to maintain common property in good and serviceable repair extends to the facade on common-property elevations, making curtain wall maintenance a governance responsibility as much as a technical one.

The height and access dimension brings its own compliance obligations. Any work on the facade above ground level is work at height, governed by the framework of duties, licensing and safe systems of work that applies to all facade access in Victoria. These obligations are set out in full in our guide to height safety compliance for Melbourne commercial buildings, and they apply to curtain wall maintenance just as they apply to any other task performed on the face of a high-rise building.

Access: The Defining Constraint in Curtain Wall Maintenance

Access is the factor that most shapes how curtain wall maintenance is delivered, because the components that require attention sit across the entire face of a tall building, often on elevations that no internal access can reach. How a contractor reaches the facade determines what can be inspected, what can be repaired in situ, and what the work will cost.

Rope access is frequently the most efficient method for curtain wall maintenance on Melbourne high-rise buildings. IRATA-certified technicians can position themselves precisely against any point on the facade, inspect gaskets and sealant joints at close range, assess structural silicone condition, clear blocked drainage, and carry out sealant replacement without the mobilisation cost and footprint of scaffolding or a building maintenance unit. This is the same access discipline that underpins high-rise window cleaning, and it means the routine window cleaning programme and the curtain wall maintenance programme can share access, personnel and knowledge of the building rather than being commissioned as unrelated exercises.

The connection between cleaning and maintenance is more than logistical. A technician cleaning the glass of the facade is positioned at exactly the joints, gaskets and seals that a maintenance regime must monitor, and a competent contractor treats every cleaning visit as an opportunity to observe the facade’s condition and flag emerging defects. This is the principle explored in depth in our guide to facade inspections during window cleaning, and it applies with particular force to these systems, where early detection of a failing seal can prevent a water-ingress event that costs many times the price of the repair. Folding curtain wall maintenance into an ongoing window cleaning and building maintenance relationship is one of the most effective ways a facilities manager can protect a glass-fronted building.

Structuring a Curtain Wall Maintenance Programme

A defensible approach to curtain wall maintenance is a structured programme rather than a reactive response to visible problems, because by the time a facade failure is visible inside a tenancy, the cost has already escalated. The programme should combine periodic detailed inspection with continuous monitoring during routine facade works, producing a documented record of condition that supports both maintenance planning and compliance reporting.

A periodic detailed inspection, conducted at an interval suited to the building’s age, construction and exposure, examines the facade systematically: sealant and gasket condition across the elevations, structural silicone integrity where applicable, drainage path function, fixing and bracket condition, and the state of the glazing units. Buildings in high-exposure coastal locations and older buildings approaching the end of their original sealant life warrant shorter intervals. Between these detailed inspections, the routine window cleaning programme provides continuous low-cost monitoring, with technicians flagging any change they observe at close range. This two-tier structure, formal periodic inspection supported by ongoing observation, is the framework within which curtain wall maintenance delivers the most value, and it aligns with the broader scheduling discipline set out in our guidance on annual safety inspections for high-access buildings.

When the programme identifies a defect, the response should be proportionate and prompt. Failed perimeter sealants and gaskets are replaced before they admit water. Compromised structural silicone is assessed and remediated as a priority given its role in glazing retention. Blocked drainage is cleared and reinstated. Corroded fixings are addressed before they threaten the load path. Documenting each intervention completes the record and feeds the following year’s compliance reporting, demonstrating that the building owner is actively managing the facade rather than waiting for it to fail.

The Economics of Preventive Versus Reactive Maintenance

For facilities managers justifying a maintenance budget to building owners or an owners corporation committee, the economic case for a planned programme deserves to be made explicitly, because it is compelling once the true cost of reactive repair is understood. The visible price of a failed seal is the sealant replacement itself, which is modest. The hidden cost is everything that failure sets in motion when it is left to progress: water tracking into occupied tenancies, damage to ceilings, finishes and fitout, disruption and potential rent abatement for affected tenants, the investigation required to trace an ingress point that may be far from where the water appears, and the reputational cost of a building that visibly cannot keep the weather out. A seal that could have been replaced for a few hundred dollars during a routine visit can, once it fails and admits water for a season, generate remediation running to tens of thousands.

Preventive maintenance inverts this equation. By identifying and addressing deterioration before it admits water or threatens glazing retention, a planned programme converts unpredictable, escalating reactive costs into a modest and forecastable line in the operating budget. It also extends the serviceable life of the facade, deferring the far larger capital cost of a major recladding or reglazing programme by keeping the existing system in sound condition for longer. For a building owner, this is asset preservation in the most direct sense, protecting the value and the weathertightness of one of the most expensive elements of the building.

There is a tenancy dimension as well. Commercial tenants increasingly expect a well-managed building envelope, and water ingress into a leased space is among the most damaging failures a facilities manager can preside over, straining tenant relationships and complicating lease renewals. A visible, documented maintenance programme signals to tenants and prospective tenants that the building is professionally managed, which supports occupancy and rental performance. Framed this way, the maintenance budget is not a cost centre but a protection of the income the building generates. A facilities manager who can present the numbers this way, setting the modest cost of planned upkeep against the far larger exposure of reactive failure, will find the case for a structured programme far easier to win with owners and committees alike.

Procuring Competent Curtain Wall Maintenance

The value of curtain wall maintenance depends entirely on the competence of the provider, and this is where facilities managers exercise the most consequential judgement. It is a technical system, and a contractor who treats it as ordinary glass and framing will miss the failure modes that matter. Selecting the right provider is a risk-management decision in its own right.

The first consideration is genuine understanding of curtain wall systems. The provider should be able to identify the system type, explain how it manages water, assess structural silicone and drainage as well as surface sealants, and distinguish a facade weather-seal failure from an insulated glazing unit failure. Generalist cleaning contractors frequently lack this depth. The second consideration is access capability. A provider that can only reach part of the facade will deliver only partial curtain wall maintenance, and the components most prone to failure are often the least accessible. IRATA-certified rope access, delivered under proper height safety controls and a documented safe work method statement, is what allows a complete programme across the full height of the building.

The third consideration is integration and documentation. A provider whose capability spans window cleaning, facade repairs, glazing assessment and height safety can move from inspection to remediation without a fresh procurement and a new access mobilisation, and can fold curtain wall maintenance into a single ongoing relationship that also covers cleaning and broader building maintenance. That continuity means the contractor accumulates knowledge of the building over successive visits, holds the inspection history, and detects change that a one-off inspector would miss. Appropriate public liability insurance and current high-risk work licensing for the access methods employed are non-negotiable, and the provider should deliver written reports with photographic evidence, a defect register and prioritised recommendations a facilities manager can act on and defend.

For Melbourne facilities managers, property managers and owners corporations, a disciplined approach to curtain wall maintenance protects the building fabric, the tenancies within it and the substantial asset value that a glass-fronted high-rise represents. It prevents the water-ingress events that disrupt tenants and generate remediation costs far exceeding the price of timely repair, and it satisfies the compliance obligations that bear on the condition of the external envelope. Engaging a specialist contractor with genuine curtain wall expertise, IRATA-certified rope access capability, and integrated window cleaning, facade and building maintenance services means a single relationship can cover inspection, monitoring and remediation across the life of the building. To arrange a curtain wall maintenance assessment for your building, or to discuss integrating facade condition monitoring into your window cleaning programme, call us today on 1300 30 15 40.