AS 4773.2:2018

AS 4773.2 is rarely directly applied in TRSC's commercial-asset practice, but it becomes important in three categories of engagement: heritage residential masonry assessment (heritage cottages, Queenslanders with masonry sub-floor and lower-storey elements), Class 1 to Class 9 reclassification (small residential masonry being converted to commercial use), and post-disaster small-building masonry assessment. For larger commercial masonry buildings, AS 3700 (the engineering-design masonry standard) is the controlling reference, but AS 4773.2 construction-side provisions inform inspection methodology and workmanship-acceptance criteria for any masonry construction. Three application points matter when AS 4773.2 is relevant. First, the standard's workmanship tolerances (course alignment, mortar joint thickness, plumb and level acceptance) are the basis for inspection-based assessment of as-built masonry quality. For heritage masonry where original construction predates AS 4773.2, the as-built workmanship is assessed against the standard's tolerances, with the resulting deviations documented as part of the structural condition assessment. Heritage masonry frequently shows out-of-plumb and out-of-level conditions that exceed AS 4773.2 modern tolerances, and the assessment must determine whether these deviations are evidence of original-construction practice (acceptable for heritage retention) or of subsequent settlement and movement (decision-controlling for structural intervention). Second, AS 4773.2 control-joint provisions are decision-controlling for restraint-of-shrinkage assessment in large masonry walls. The standard prescribes maximum spacing of vertical control joints (typically 6 m for clay brick, 7.5 m for concrete masonry, with reductions in restrained or shaded conditions) to manage shrinkage-induced cracking. Pre-2010 masonry frequently has inadequate or absent control joints, and the resulting shrinkage-induced cracking can be misdiagnosed as structural movement. TRSC's masonry condition assessments include explicit control-joint review against AS 4773.2 spacing, and where shrinkage-induced cracking is the diagnosed mechanism, remediation involves retrofit control-joint installation (typically saw-cut joints with backer-rod and sealant) rather than structural intervention. Third, AS 4773.2 lintel and bond-beam provisions are decision-controlling for opening-related masonry capacity assessment. The standard prescribes lintel-bearing length, bond-beam reinforcement and lintel-to-jamb integration; pre-2010 small-buildings masonry frequently has lintel construction (typically uncovered angle-iron or hollow-section lintels above window and door openings) that does not meet current AS 4773.2 provisions. For continuing-life certification, the as-installed lintel capacity is assessed against the design imposed action with the AS 3700 capacity equations applied to the as-built geometry, and where capacity is inadequate, retrofit involves either supplementary lintel installation or beam-and-jamb replacement.