How We Saved This Client Money
This is a scenario we encounter regularly in Sydney remedial waterproofing work. The details below are generalised to protect client confidentiality, but the situation, investigation process, and outcome are representative of a common pattern we see in strata buildings across the Sydney metropolitan area.
The Situation
An owners corporation for a mid-rise residential building (Class 2, approximately 15 years old) was dealing with water ingress complaints from multiple units. Residents on several levels had reported water staining and, in some cases, active dripping on their ceilings — all located below balconies on the levels above.
The strata committee had engaged a building contractor to inspect and quote on the problem. The contractor’s recommendation was full strip-out and replacement of all eight balconies on the affected facade: removal of tiles, screed, and existing membrane, followed by new waterproofing, screed, and tiling. The quoted cost was substantial — well into six figures — and would require a significant special levy from lot owners.
Before committing to that expenditure, the strata manager sought a second opinion. That is where we became involved.
The Investigation
We carried out a systematic inspection of all eight balconies and their corresponding soffits below. The investigation included:
- Visual inspection of each balcony: Surface condition, tile integrity, grout condition, drainage outlet function, threshold details, perimeter flashing condition, and balustrade base details were assessed on every balcony individually.
- Soffit inspection from below: Each balcony soffit was examined for water staining patterns, efflorescence, concrete spalling, and any visible cracking. The distribution and severity of staining provides important diagnostic information about the nature and extent of moisture ingress above.
- Non-destructive moisture testing: Moisture readings were taken across each balcony surface to map the extent and intensity of moisture retention within the screed and substrate.
- Falls assessment: Each balcony was checked for adequate falls to the drainage outlet, as required by AS 4654.2-2012 (minimum 1:100 surface fall).
- Targeted destructive investigation: On balconies where the non-destructive results indicated potential membrane failure, we carried out localised tile and screed removal to directly inspect the membrane condition and adhesion to the substrate.
What We Found
The results did not support a blanket replacement of all eight balconies. The investigation revealed three distinct categories of defect across the building:
Category 1: Membrane failure (3 of 8 balconies)
Three balconies had genuine, widespread membrane failure. The original liquid-applied membrane had disbonded from the substrate across large areas, and destructive testing confirmed the membrane was no longer providing a waterproof barrier. These three balconies required full strip-out and replacement — removal of tiles, screed, and failed membrane, substrate preparation, new waterproofing membrane installed to AS 4654.2-2012, new screed with correct falls, and new tiling.
Category 2: Drainage and flashing defects (3 of 8 balconies)
Three balconies had intact membranes but were experiencing water ingress due to defective perimeter flashings and partially blocked drainage outlets. In two cases, the flashing at the wall-to-balcony junction had separated, allowing water to bypass the membrane entirely and enter the slab at the perimeter. In the third case, the drainage outlet was partially obstructed by tile adhesive residue from the original construction, causing water to back up and overflow at the door threshold during heavy rain.
These balconies did not require membrane replacement. The remediation involved refixing and sealing the perimeter flashings, clearing and servicing the drainage outlets, and re-sealing the threshold details — all achievable without removing the existing tiles or membrane.
Category 3: No significant defect (2 of 8 balconies)
Two balconies showed no evidence of active water ingress. The membranes were intact, falls were adequate, and the soffits below showed no staining or efflorescence. Minor maintenance items were noted (grout repointing in isolated areas), but no waterproofing remediation was required.
The Outcome
Based on our investigation findings, we prepared a detailed scope of works that prescribed the appropriate level of intervention for each balcony individually:
- 3 balconies: Full strip-out and membrane replacement
- 3 balconies: Targeted flashing and drainage repairs
- 2 balconies: Minor maintenance only
The owners corporation tendered the works based on our scope. The final cost for the targeted remediation program was significantly less than the original blanket replacement quote — a saving that materially reduced the special levy burden on lot owners.
Equally important, the three balconies that genuinely needed full replacement received it. The investigation ensured that the money spent was directed at actual defects rather than spread uniformly across balconies that did not require that level of intervention.
The Lesson
This outcome is not unusual. In our experience with Sydney strata buildings, a blanket approach to balcony remediation — where every balcony receives the same scope of works regardless of its actual condition — is common but rarely justified. Buildings age unevenly. Balconies with different orientations, different exposure to weather, different drainage configurations, and different usage patterns will develop different defect profiles.
The value of a proper investigation before remediation is straightforward:
- It prevents overspending. Not every balcony showing symptoms requires the same treatment. A drainage defect does not require a membrane replacement. A flashing failure does not require a full strip-out.
- It prevents underspending. A balcony with genuine membrane failure that receives only a flashing repair will continue to leak. The investigation identifies which balconies truly need comprehensive work.
- It provides defensible documentation. The investigation report gives the owners corporation a clear, evidence-based rationale for the remediation scope — important for strata governance, levy justification, and any future warranty claims.
- It establishes a baseline. The investigation documents the current condition of every balcony, including those not requiring immediate work. This baseline supports the strata’s capital works planning by identifying which balconies may need attention in the medium term.
The investigation itself represents a modest cost relative to the remediation works it informs. In this case, the cost of the investigation was recovered many times over through the reduction in unnecessary replacement scope.
When to Seek an Independent Investigation
If your strata building has received a remediation quote that prescribes the same scope of works across all balconies, it is worth asking whether an independent investigation has been carried out to confirm that every balcony actually requires that level of work. A contractor quoting on remediation has an inherent interest in a larger scope. An independent consultant — one who is not tendering for the remediation work — provides an objective assessment.
Under the Strata Schemes Management Act 2015 (NSW), the owners corporation has a responsibility to maintain common property, which includes balcony waterproofing membranes. That responsibility includes ensuring remediation is appropriately scoped — neither under-done nor over-done. A proper investigation is the foundation for meeting that obligation.