Brickwork defects in Australian residential construction

What it is

Brickwork covers external and internal masonry walls in residential builds. The governing standard is AS 3700 for general masonry and AS 4773 for masonry in small buildings. The NCC adopts both as primary references for Class 1 and 10 buildings. When a tribunal in Australia reviews a brickwork claim the inspector lines the work up against these standards clause by clause.

Common defect categories

Efflorescence is the white salt deposit that appears on new brickwork. Primary efflorescence (from the mortar) is cosmetic and fades within twelve months. Secondary efflorescence (from continuing moisture ingress) is a defect. It signals water sitting inside the cavity and points to flashing or weep hole failure.

Mortar non-compliance is harder to spot but more serious. AS 3700 specifies mortar mix ratios by class. Class M3 (1:1:6 cement:lime:sand) is the standard residential mix. Class M4 (1:0.5:4.5) is required in saline or aggressive environments such as coastal NSW and QLD. Sites that use straight sand and cement without lime fail durability requirements and crack at every control joint.

Weep holes must be installed at the base of every cavity wall, above every flashing, and above every opening. They sit at maximum 1200 mm spacing under AS 3700. Crews routinely block weep holes with mortar drop during the build. Tribunal inspectors check this every time.

Articulation joints are the vertical control joints in long masonry walls. AS 3700 requires them at maximum six metre intervals on stable sites and tighter on reactive sites. Their absence is the single most common cause of step cracking in NSW and VIC tribunal cases.

Who is liable

Brickwork defects sit inside both warranty windows. Major structural failure such as a leaning wall or a wall pulling away from the frame triggers the six-year major defect warranty. Cosmetic issues such as efflorescence or poor pointing fall inside the two-year non-structural window in most states. The builder carries the obligation. Bricklayer subcontractors are usually pursued by the builder under their trade contract.

NCAT decisions show tribunals award full re-rendering or rebuilding of sections where mortar is below specification. VCAT routinely orders builders to reinstall flashings and weep holes at full cost. QCAT applies the QBCC Standards and Tolerances Guide which sets specific limits on out-of-plumb, bowing and joint width tolerances.

TradeLens risk flags

Files should be flagged when any of these are missing or wrong. Site classification not matched to articulation joint spacing. No flashing detail at base of wall or above openings. Mortar mix specification absent from the build file. Bricklayer supervisor not nominated. Cavity not inspected before slabbing the next course. These five gaps drive most successful claims.

Typical rectification cost

Cleaning efflorescence is 1000 to 3000 dollars per elevation. Cutting in missing articulation joints is 4000 to 12000 dollars depending on length. Replacing a non-compliant wall section is 250 to 450 dollars per square metre of brickwork. Full elevation rebuilds run 30000 to 80000 dollars and are the largest single category of brickwork tribunal awards.