Aluminium Window and Façade Inspection: Drainage, Seals, Glazing and Service Records

An aluminium window or façade rarely fails in a single dramatic moment. It declines slowly. A gasket takes a permanent set, a weep slot silts up, a sealant bead loses adhesion at one corner, a roller flattens, a coastal elevation begins to pit. Individually these are small observations. Together they decide whether a building stays dry, quiet, efficient and safe over its service life.

This guide sets out how to inspect aluminium windows and façades, what to examine and in what order, how to record what you find, and how to turn observations into planned maintenance rather than emergency repair. It is written for owners, facility managers, builders, architects and strata committees who need a practical method rather than a textbook. It is also written from a manufacturer’s perspective: Meichen has supplied aluminium window and door systems to the Australian and New Zealand markets since 2017, and the questions we receive most often are not about how a product performs on the day it is installed, but about how to keep that performance intact years later.

What an Inspection Is Actually For

An inspection is a structured, evidence-producing check that an installed assembly still does what it was specified to do. That definition separates inspection from casual looking. Casual looking notices the obvious — a cracked pane, a handle that will not turn. An inspection works through a defined scope, in a defined order, and produces a record that another person could read and act on.

The purpose can be stated in four plain functions, and every observation you make during a walk-through should attach to one of them.

• Weathertightness. The assembly must shed water outward and resist air movement under the conditions it was designed for. Seals, drainage paths and pressure equalisation are the mechanisms that achieve this.
• Structural continuity. Glass, frames, fixings and the surrounding structure must continue to transfer wind load and self-weight safely, including allowance for movement.
• Operation and safety. Openable sashes, doors and hardware must operate as intended, and safety glazing, restrictors and balustrade elements must remain effective.
• Durability and evidence. The finish, the components and the documentation must remain in a condition that supports the owner’s warranty position and long-term planning.

Separating inspection from service

Inspection is observation, measurement where appropriate, and recording. Service is intervention: cleaning drainage paths, replacing a gasket, adjusting a roller, re-sealing a joint. Keeping the two activities distinct is useful because they answer different questions. An inspection asks “what is the condition?” A service asks “what needs doing, and by whom?” When the two are merged without records, a building ends up with a maintenance history that exists only in someone’s memory.

Why the purpose must be defined before the walk begins

A defect survey for a warranty claim, a pre-purchase condition report, a post-storm assessment and a routine annual review all look at the same windows, but they do not look for the same things in the same depth. Defining the purpose first determines the access required, the level of disassembly permitted, the photographic standard, and who must sign the report. An inspection without a stated purpose produces observations without priorities, and priorities are the only part a budget can act on.

Starting With a Systematic Visual Walk-Through

Visual inspection is the highest-value, lowest-cost tool available, provided it is done systematically rather than by wandering the elevation. The objective is to compare like with like: every unit of the same type should be examined in the same way, at the same distance, under similar light.

Work the elevation in a fixed pattern

Begin at one corner and move in a consistent direction — left to right, bottom to top, or by grid reference taken from the architectural drawings. Record each unit against its identifier rather than its description. “Level 3, grid C4, unit W-12” is a record; “the window near the stair” is an anecdote. Where drawings are unavailable, create a simple elevation sketch and number the openings before starting, so that every later note and photograph can be tied back to a location.

Read the building for patterns, not just defects

Individual defects matter, but patterns tell you more. Staining that repeats at the same sill on every level points to a detail rather than a one-off installation error. Dirt tracking down one jamb across several floors suggests a concentrated leak path or an architectural ledge above. Corrosion confined to one elevation usually reflects prevailing weather rather than a batch of faulty components. Patterns also protect against the opposite mistake: assuming a single wet patch means the whole system has failed.

What to photograph and note

Photograph the whole unit in context, then the specific detail, then a scale reference where size matters. Note the viewing direction and the time of day, because raking light reveals distortion, ponding and surface deviation that flat light hides. Record what you did not inspect as carefully as what you did. Access limitations, closed tenancies, locked rooms and areas above safe reach are all findings in their own right, and omitting them turns a partial inspection into a misleading one.

Seals and Gaskets: The First Line of Defence

Most water and air leakage in aluminium systems begins at a seal. Seals fall into two broad families: pre-formed gaskets, usually EPDM, which rely on compression between frame and sash or between glass and frame; and wet-applied sealant joints, which rely on adhesion and on the joint’s ability to accommodate movement without tearing.

Compression, continuity and corner condition

Gaskets work because they are compressed. Once compression is lost — through permanent set, shrinkage, or a sash that no longer closes squarely — the seal becomes a gap with a memory of being tight. Look for gaskets that sit proud of their rebate, that have pulled back at corners, that are hardened or crazed, or that show a continuous polished line where they have been rubbing. Corners deserve particular attention: a mitred gasket corner that has opened is a direct path for water driven by wind pressure.

Sealant joints are not a substitute for drainage

Perimeter sealant joints accommodate movement between the window frame and the surrounding structure. They should be inspected for adhesion loss at the bond faces, cohesive cracking through the bead, and evidence of the bead being stretched or compressed beyond what the joint was designed for. A common failure pattern is a joint that looks intact but has debonded behind the visible surface, allowing water to travel behind the bead. Pressing gently along the joint line, where access and safety permit, will often reveal a void that a photograph cannot.

It is worth stating plainly: sealant is a barrier, not a drainage system. A joint that is re-sealed over a blocked drainage path traps water rather than excluding it. Any sealant repair should be preceded by a check that the water has somewhere to go.

Drainage, Weeps and Pressure Equalisation

Aluminium window and door systems are designed to collect the small amount of water that passes the outer seal and discharge it outward through controlled openings. That design only works while the path remains open. Drainage inspection is therefore less about finding water and more about confirming that water can leave.

Trace the drainage path

For each system type, identify where water enters the frame, where it is intended to travel, and where it exits. On sliding systems, the track itself is usually the collection channel. On awning and casement systems, the sill chamber behind the external leg is typically the collection zone. On curtain wall systems, each panel or spandrel zone has its own drainage route that must remain independent of the one above. Understanding the intended route is what allows you to judge whether an observation is normal or abnormal.

Blocked weeps and hidden ponds

Weep slots and drainage openings block with pollen, leaf litter, insect nests, render and mortar droppings, and sealant applied by well-meaning trades during later works. A blocked weep does not always produce an immediate leak. Water sits in the chamber, finds the weakest seal, and appears indoors some distance from the actual obstruction. This is why internal damp patches should never be diagnosed from the inside alone.

Where a baffle or pressure-equalisation slot is fitted, check that it is present, correctly oriented and not painted shut. Pressure equalisation reduces the pressure difference that drives water inward, so a compromised slot can turn a minor seal defect into a persistent leak. Clear obstructions with non-abrasive tools, and avoid enlarging openings, which changes the designed flow path.

Glazing: Glass, Setting Blocks and Edge Protection

Glass is the largest single component of most façades, and the glazing detail is where structural performance, weathertightness and safety intersect. Inspection should cover the glass itself, the way it is supported, and the way it is sealed into the frame.

Reading glass condition

Note cracks, chips and edge damage, and record where each defect starts. Damage originating at an edge often indicates contact with the frame, a hard setting block, or a nicked edge from handling. Damage away from edges has other causes and deserves closer assessment. Scratches, weld spatter, and abrasion from cleaning equipment are cosmetic until they compromise the surface, but they should still be recorded because they affect appearance and, in coated products, long-term durability.

Setting blocks, cover caps and glazing tape

Setting blocks carry the weight of the glass and keep its lower edge clear of the frame. If a block has extruded, hardened, or shifted, the glass may be bearing directly on aluminium or on a fixing — a condition that concentrates stress and can lead to breakage. Cover caps and pressure plates should be seated and complete; missing caps expose fasteners and gasket edges to weather and ultraviolet light. Glazing tape and wet glazing should show continuous contact without voids, and drained-and-ventilated cavities should remain open at both the head and the sill.

Insulating glass units

For double and triple glazed units, look for fogging, internal condensation, dust ingress between panes, and visible deterioration of the edge seal. These indicate that the unit’s sealed cavity has been compromised. Once moisture is inside the cavity, the unit’s thermal performance and appearance both degrade, and the condition cannot be corrected by cleaning. Record the affected units individually, because replacement is a per-unit decision.

Glass selection and installation are governed by AS 1288, with safety glazing requirements addressed through AS 2208 where those requirements apply. An inspection does not re-certify the original selection, but it should confirm that glass in identified locations remains the type shown on the documentation, particularly after any replacement.

Frame Movement, Fixings and Structural Behaviour

Aluminium moves. It expands and contracts with temperature, it deflects under wind load, and it sits within a building structure that also moves. A well-designed installation accommodates that movement; an inspection looks for evidence that the accommodation is still working.

Movement joints and building drift

Check that movement joints remain open and free of rigid material. Joints packed with mortar, sealant or debris stop being joints and start transferring load into the frame. On multi-storey buildings, look at how the façade meets the slab edge at each level: inter-storey drift and slab deflection are absorbed at these interfaces, and any sign of binding, cracking or local deformation there deserves engineering assessment rather than a maintenance fix.

Fixings, packers and dissimilar metals

Fixings should be present, engaged and consistent with the documented schedule. Look for missing screws, corroded fasteners, elongated holes, and packers that have fallen out or been crushed. Where aluminium contacts steel or another metal, isolation should be in place; breakdown of that isolation is a common starting point for galvanic corrosion. As a general principle, fixings into the structure are specified by the engineer and installed to the project’s documented details, and any deviation found during inspection should be referred back rather than improvised on site.

AS 4666 addresses the installation of windows and doors in buildings, and it is the reference point for how the frame is expected to be fixed, sealed and integrated with the surrounding construction. When an inspection finds a fixing or interface condition that does not match the documented installation, the standard and the project’s installation details together provide the benchmark for the repair.

Hardware and Operable Elements

Hardware is the part of the system that occupants touch every day, and it is usually the first to show wear. It is also the part most often adjusted by non-specialists, which makes systematic inspection worthwhile.

Operation as a diagnostic

Operate every openable element through its full range, where access and safety allow. A sash that binds at one point, drops at the handle side, or requires force to latch is telling you something about alignment, fixing or roller condition. Sliding doors should run without grinding and should pull into the jamb without being lifted. Awning and casement windows should close against the gasket evenly, not at one corner first. Tilt and turn windows should change mode cleanly. Bi-fold doors should fold and stack without the panels contacting each other.

Component-level checks

Inspect rollers and tracks for flat spots, debris and wear. Check locking points, keepers and multipoint gear for engagement and alignment. Examine handles, hinges, friction stays and restrictors for looseness or corrosion. Confirm that restrictors and safety devices are fitted where they were specified and have not been removed. Lubricate only with products compatible with the system’s components; the wrong lubricant can attract dust or degrade seals.

Hardware findings should be recorded by component and by unit, because replacement parts are matched to the system. A generic replacement may fit physically but perform differently, particularly where the hardware was selected for the Australian or New Zealand market.

Corrosion and Coastal Exposure

Aluminium protects itself with a thin oxide layer that re-forms when damaged. In coastal environments, airborne chloride interferes with that process and shifts the balance toward pitting and surface deterioration. The visible result is often staining, white corrosion product, or a chalky appearance on powder-coated surfaces, but the more important question is whether the protective finish is intact at edges, cut ends and fixing points.

What to look for on a coastal elevation

Inspect cut edges, drilled holes, scribed lines and areas where the coating has been damaged during construction. These are where corrosion usually starts. Look for rust staining around fasteners, which may indicate that the fastener rather than the aluminium is corroding. Check the bases of frames, sills and lower tracks, where salt-laden water and debris collect, and examine the junctions between dissimilar materials.

Cleaning as part of the inspection outcome

Deposited salt holds moisture against the surface and keeps the corrosion process supplied. Removing it is one of the few maintenance actions that directly addresses coastal exposure. The cleaning method should suit the finish — mild detergent and fresh water, non-abrasive tools, and no aggressive agents that attack the coating. The appropriate cleaning frequency depends on proximity to the coast, prevailing wind, shelter and the finish itself, so it should be set for the individual building rather than applied as a universal rule. The inspection should record whether the observed condition suggests the current regime is adequate.

Meichen’s own product information notes that the systems are intended for Australian and New Zealand conditions, including coastal applications where the correct finish and hardware specification is selected. Specification and maintenance have to work together; the best finish available will still deteriorate if salt is allowed to sit on it indefinitely.

Condensation: Distinguishing Symptoms From Causes

Condensation is the most frequently misdiagnosed condition on any window inspection. Water on glass or in a track is treated as evidence of a leak, when it may be evidence of humidity, ventilation or thermal bridging. Getting the diagnosis right prevents unnecessary re-sealing and identifies the intervention that will actually work.

Surface condensation

Condensation on the room-side surface of glass or frame occurs when the surface temperature falls below the dew point of the indoor air. It concentrates at the coldest points: frame edges, spacers, and the bottom of the glass where cool air pools. Frames with thermal breaks and units with better insulating glass reduce the likelihood, but no window can prevent condensation in a room with high humidity and poor ventilation. The inspection should record where the moisture appears and whether it correlates with cooking, bathing, drying clothes or occupancy patterns.

Condensation inside the unit

Moisture between the panes of an insulating glass unit is a different matter. It indicates that the edge seal has failed and the desiccant is saturated. This is a unit defect, not a ventilation problem, and it will not clear. Record it as such, with photographs and unit identifiers, so that replacement can be planned.

What condensation can mask

Persistent moisture also hides other problems. It can initiate mould growth on surrounding plaster, corrode hardware, and obscure the early signs of a genuine leak. Where condensation is chronic, the inspection should note the underlying ventilation and humidity conditions rather than treating the window as the sole cause.

Curtain Walls and the BA150 Product Line

Curtain walls combine the functions described above at building scale, and they add interfaces that a window inspection does not encounter. Within Meichen’s product range, the curtain wall line is designated BA150. That designation identifies the product family; the performance of any particular installation depends on the project-specific engineering, the tested system configuration and the quality of installation, and should be read from the project documentation rather than inferred from the name.

Interfaces are where curtain walls fail

Most curtain wall water problems occur at interfaces rather than in the middle of a panel: at the head and sill, at expansion joints, at the junction with opaque construction, at parapets and at openings for doors and louvres. Inspection should follow the interface line around each elevation and check that seals are continuous, that movement joints remain free, and that drainage from one zone is not discharging into another.

Access and safe inspection of high-level façades

High-level façade inspection requires a planned access method: elevated work platforms, rope access, building maintenance units, or internal access where the design provides it. The method determines what can be seen, so it should be chosen to match the purpose of the inspection, and it must comply with work health and safety requirements. Photographic records from a distance are useful for mapping, but they cannot confirm gasket compression or sealant adhesion. Where close inspection is not possible, say so in the report.

Service Records: What to Keep and Why

A service record is the memory of the building. It converts a series of observations into a history that supports warranty claims, budgets, dispute resolution and informed decisions about replacement. Records are also the difference between maintenance that is planned and maintenance that is merely repeated.

The minimum data set

For every opening or façade zone, maintain an asset entry that can be matched to the drawings. At a minimum, record the location identifier, the product series and configuration as installed, the glass type and makeup as installed, the finish, and the date of installation. For each inspection, record the date, the inspector and their competence, the access method, the observations by asset identifier, the photographs, and the actions recommended or completed.

Making records usable

Records fail when they cannot be found, cannot be read, or cannot be linked to a location. Use the same identifiers as the drawings, store photographs with the asset identifier in the file name, and keep a single index. A short, consistent record repeated over years is far more valuable than a detailed report that is never updated.

Repair Escalation: From Observation to Action

An inspection that does not lead to a decision has no value. Escalation is the process of moving an observation from the report into the right level of response, with the right person accountable and a defined timeframe.

A practical severity framework

• Monitor. Cosmetic or early-stage conditions with no effect on performance: minor finish marks, early sealant weathering, light staining. Record, photograph and re-check at the next inspection.
• Routine repair. Conditions that will affect performance if left: partial blockage of drainage, localised gasket deterioration, hardware adjustment, isolated sealant debonding. Schedule into planned maintenance.
• Urgent. Active water ingress, failed glazing seals, non-operating hardware on access or egress windows, or corrosion advancing at fixings. Attend promptly and protect the interior in the interim.
• Emergency or safety-critical. Loose or displaced components at height, cracked glass in a trafficable or overhead location, compromised balustrade or restrictor hardware, or any condition with a risk of falling material. Isolate the area and obtain competent advice immediately.

Who does what

Separate the roles of observer, assessor and repairer. The observer records condition. The assessor determines cause and scope, and may need an engineer where structure, movement or glass behaviour is involved. The repairer carries out work to the system’s documented details and records what was done. Where a repair affects the tested configuration — changing glass, altering drainage, or substituting hardware — the manufacturer or supplier should be consulted before work proceeds.

Maintenance Planning Across the Asset Life Cycle

Maintenance planning turns inspection findings into a forward programme. The aim is not to eliminate all work, but to move as much of it as possible from reactive to planned, where it can be scoped, priced and scheduled on the owner’s terms.

Prioritise by exposure and consequence

Not every elevation deserves the same attention. Coastal façades, elevations facing prevailing weather, high-level areas with difficult access, and locations where a leak would damage valuable interiors all warrant closer scrutiny. Consequence matters as much as likelihood: a failed seal above a switchboard is a different problem from the same seal above a tiled balcony.

Budget, access and spares

Access is often the largest cost in façade maintenance, so grouping work by access method is more efficient than addressing items one at a time. Keep a small stock of the correct consumables — gaskets, sealant, fasteners and hardware matched to the installed systems — so that minor repairs are not deferred while parts are sourced. Record the outcome of every intervention, because a repair that recurs is a diagnosis problem, not a maintenance problem.

Feedback into the next project

Maintenance records are also design feedback. If one detail consistently collects debris, or one interface consistently leaks, that information is valuable at the specification stage of the next project. Manufacturers see this pattern across many buildings, which is why installation detail and drainage design receive as much attention as profile appearance.

Standards and Regulatory Context

Inspection does not exist in a vacuum. The benchmarks used to judge condition come from the standards and code framework under which the building was designed and approved.

Australia

The National Construction Code (NCC), administered by the Australian Building Codes Board (ABCB), sets the performance framework for construction. Within it, AS 2047 provides the performance requirements for windows and doors in buildings, AS 1288 governs glass selection and installation, AS 2208 addresses safety glazing materials, AS 4284 provides the test method used to demonstrate façade and window performance under simulated wind and water conditions, and AS 4666 addresses installation. Together these documents describe what the assembly was required to achieve and how it should have been installed. They do not, by themselves, set an inspection timetable for an existing building; that comes from the project documentation, the maintenance manual and the owner’s obligations.

New Zealand

In New Zealand, SNZ TS 4211:2022 provides the technical specification for window performance, and SNZ 4223 provides the code of practice for glazing in buildings. Buildings designed and consented under these documents should be inspected against the performance and detailing they describe, with particular attention to glazing selection, support and protection.

What standards do and do not tell you

Standards define performance and method. They do not tell you that a particular gasket on a particular elevation has lost compression. That judgement comes from inspection, recorded against the standard as a reference point. This is also why product certification matters at the point of specification: Meichen’s published information records 43 product series certified for Australia and 13 product lines certified for New Zealand, and those certifications describe tested configurations. If a repair or replacement departs from the tested configuration, the certification may no longer describe what is on the building.

Reading test data in context

Test results describe performance under defined conditions. Meichen systems have been tested to water tightness levels of up to 960 Pa under AS 4284, which reflects the capability of the tested assemblies. On site, the same system performs only as well as its installation, its drainage paths and its seals allow. This is the practical reason inspection and maintenance deserve the same attention as the original specification.

Frequently Asked Questions (FAQ)

How often should aluminium windows and façades be inspected?

There is no single correct interval, and any number chosen without reference to the building would be arbitrary. The schedule should reflect exposure to salt and weather, building height and access difficulty, occupancy and internal humidity, the manufacturer’s maintenance recommendations, warranty conditions, and the consequences of failure. Reviews should also be triggered by events rather than only by calendar: a severe storm, an impact, a renovation that alters drainage, or a change of use that raises internal moisture.

Can building staff carry out the inspection themselves?

Staff can and should carry out routine visual observation, provided they have a checklist, a consistent recording method and clear escalation criteria. Anything involving work at height, operation of large sashes, removal of glazing beads, or diagnosis of structural movement should be done by a competent person under appropriate safety arrangements. The value of in-house observation is continuity; the value of specialist involvement is judgement.

Water sits in the door track after rain. Has the door failed?

Not necessarily. Sliding systems are designed to collect and discharge water, and some residual moisture in a track is normal. The question is whether it clears. If water remains for long periods, overflows inward, or leaves staining, check for blocked drainage openings, debris in the track, a failed seal at the sill, or a fall that has been altered. A track that drains slowly is a maintenance item; a track that discharges inward is a defect.

Is condensation on the inside of the glass a sign of a faulty window?

Usually not. Condensation on the room-side surface is driven by indoor humidity, ventilation and surface temperature. It is a signal to review how the space is ventilated and how moisture is managed. Condensation or fogging between the panes is different: it indicates a failed sealed unit and requires replacement of that unit.

How do I know whether a sealant joint needs replacing?

Judge by condition, not by age alone. Replace when there is adhesion loss at the bond faces, cracking through the bead, a joint that has been stretched or compressed beyond its working range, or a joint that no longer accommodates movement. Preparation matters as much as the product: the joint must be clean, dry and correctly backed, or the new sealant will fail in the same place.

What records should be handed over at completion?

As-built drawings showing every opening and façade zone, the installation details actually used, product and glass schedules, test reports and certificates for the systems supplied, maintenance and cleaning instructions, warranty documents, and a register that links each opening to its product and glass configuration. These documents are what make later inspections meaningful.

Why does coastal exposure require more attention?

Airborne chloride interferes with the protective oxide layer on aluminium and accelerates corrosion at edges, cut surfaces and fixing points. It also leaves deposits that hold moisture against the surface. The response is specification at the design stage and a cleaning and inspection regime suited to the exposure at the maintenance stage. Neither alone is sufficient.

Can a window be repaired without affecting its certification?

That depends on what is being changed. Replacing a gasket or a roller with the correct component restores the installed condition. Changing glass type, altering drainage, or substituting hardware may take the assembly outside the tested configuration. Where a repair is more than like-for-like, consult the supplier or manufacturer before proceeding.

Conclusion

Aluminium windows and façades perform well when three things stay aligned: a design that manages water and movement, an installation that follows the documented details, and a maintenance regime that observes and records what is actually happening on the building. Inspection is the link between the last two. It is not a search for faults to argue about; it is the routine practice that keeps a tested system performing as tested.

The method is straightforward. Define the purpose before the walk. Work the elevation systematically and record by identifier. Check seals for compression and continuity, and check that water can leave. Look at how glass is supported, how frames move, how fixings are isolated, and how hardware operates. Treat corrosion and condensation as diagnostic questions rather than verdicts. Keep records that another person could use. Escalate findings by severity, and let those findings shape a planned programme rather than a series of emergencies.

Done consistently, this is unglamorous work with a measurable return: fewer leaks, longer service life for seals and hardware, a defensible warranty position, and a building that still looks and performs as it was intended to, years after handover.

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