Remedial works at a six-unit building in Mosman have sealed chronic leaks, repaired concrete damage and modernised street appeal, all while normal building-maintenance routines stayed on schedule. MJ Engineering Projects designed and supervised a programme that combines upgraded flashings and membranes with new balustrades, windows and doors. Protective acrylic coatings and improved drainage now defend exposed brick façades and balconies against rain and UV, giving residents a safer, more durable home.
Project Background
The 1970s complex features load-bearing brickwork and cantilevered concrete balconies that had begun to crack and stain. Investigations by MJ Engineering Projects revealed multiple defect sources: failed deck membranes, corroded reinforcement at slab edges, non-compliant flashings and wall cavities pierced by unsealed pipes and conduits. Insurers warned they would withdraw cover unless critical risks were addressed. To meet budget constraints, our remedial design practitioners prioritised the highest-risk items and produced a staged specification that aligns with the National Construction Code (NCC) and Australian Standards.
Scope of Remedial Works
-
Waterproof the upper deck
-
Remove and replace balcony balustrades
-
Waterproof and tile balconies
-
Replace windows and doors
-
Apply medium-build acrylic coatings
-
Apply low-sheen acrylic coatings
-
Repaint timber and metal elements
-
Rectify wall-cavity vents
-
Repair concrete spalling
-
Replace cavity flashings
-
Repair delaminated render
-
Repair wall cracking
-
Apply joint sealant
Key Challenges and Solutions
Non-compliant construction details
Original wall cavities contained numerous unsealed penetrations for services, breaking the waterproof plane. MJ Engineering Projects specified custom stainless collars and a torch-on cavity flashing that laps behind brick ties and folds into the new deck membrane. All penetrations were individually sealed, and smoke tests confirmed a continuous barrier.
Tight insurance deadline and limited budget
The insurer required proof that life-safety and moisture risks were under control before renewal. MJ Engineering Projects used value-engineering workshops to rank defects by consequence and likelihood. Upper-deck waterproofing, spalling concrete and flashing were completed first and signed off by our superintendent, unlocking a staged funding release so the owners corporation could keep cash flow steady.
Balcony and deck waterproofing
Balconies leaked into living rooms below. We supervised the removal of tiles, applying a flexible sheet membrane and laying a grout-bonded screed with new falls. Porcelain tiles provide slip resistance, and stainless strip drains discharge directly to downpipes. Flood tests demonstrated watertightness, satisfying NCC performance requirements.
Concrete spalling repair
Carbonation reached reinforcement along balcony noses. After cutting out unsound concrete, we supervised the passivation of steel and reinstatement of cover with polymer-modified mortar. Medium-build acrylic coatings bridge hairline cracks and protect adjacent concrete from future carbonation.
Aesthetic integration
New windows, doors and balustrades meet modern crowd-load and energy requirements yet respect the building’s brick aesthetic. Low-sheen acrylic paint matches existing colour while giving UV stability, and repainted timber trims restore original detail without altering heritage character.
Conclusion
The Mosman remedial-works programme sealed deck and cavity leaks, repaired spalling concrete and updated safety elements without disrupting residents or routine building maintenance. Balconies now drain correctly, façades are protected by advanced coatings and stainless balustrades meet current standards while improving appearance.
MJ Engineering Projects draws on more than fifteen years of remedial-works experience to balance durability, compliance and budget for Sydney property owners. Visit our blog for additional case studies or contact the remedial works team for tailored advice on waterproofing, concrete repair and façade maintenance.
