Leak Masters Building Durability Index

A practical water-ingress risk score based on building design features that commonly predict leaks, future maintenance burden and long-term repair cost.

Philosophy: Buildings do not usually leak by accident. Certain design choices — balconies over habitable rooms, flat roofs, parapets, planter boxes, exposed windows and complex lightweight cladding — reliably increase the likelihood of water ingress over time.

Score a Building

Select the features that apply. The score updates instantly. A lower score indicates higher likely leak risk and maintenance burden.

Roof Design

Flat roof or very low-pitch roof Parapet walls Box gutters or internal gutters Complex roof geometry with multiple junctions Simple pitched roof with external gutters

Balconies, Decks & Planters

Balcony over habitable room Rooftop deck or trafficable roof membrane Integrated planter boxes or roof garden Flush threshold to balcony or external deck

Walls & Cladding

Lightweight express-joint sheet cladding Novel or unproven cladding system No eaves or minimal eave overhang Second-storey wall discharging over lower roof/wall junction Conventional cavity brick or proven drained wall system Generous eaves or verandah protection

Windows & External Doors

Exposed timber windows without soffit/eave protection Large full-height glazing exposed to weather Aluminium windows with complex sub-sill/extrusion detailing External doors exposed directly to weather Windows protected by eaves, verandahs or deep reveals

History & Maintenance

Known previous leak history Visible cracking, staining, mould or swollen linings Poor access for inspection or maintenance Building over 10 years old with limited maintenance record

Your Durability Score

100/100

Excellent

Simple, proven construction with low apparent water-ingress risk.

Category Scores

Roof

Balcony / Deck

Walls / Cladding

Windows / Doors

History / Maintenance

Primary Risk Drivers

No major risk drivers selected.

Leak Masters view:
Durable buildings are usually simple buildings. Water should be shed externally, not managed by hidden membranes and perfect workmanship.

This index is a general design-risk guide only. It is not a building inspection, compliance certificate or warranty assessment. Actual leak risk depends on design, workmanship, exposure, materials, age and maintenance history.