Problem
A significant interwar brick apartment building with stepped cracking over window heads on the street elevation — classic lintel jacking, where corroding steel lintels expand and lift the masonry above. A previous repair had repointed the cracks in hard cement mortar, which held just long enough to hide the progression and damaged the brick arrises in the process.
Diagnosis
Investigation openings at four representative window heads confirmed corroding mild-steel lintels with heavy section loss, plus cavity ties corroded at the same detail line. Mortar analysis established the original lime-rich mix for permit-compliant repointing. The condition report and proposed methodology were prepared to support the OC’s heritage permit application, with the heritage consultant.
Method
Sequenced masonry support and dismantling above each affected opening, brick-by-brick with units numbered for reinstatement in position. Corroded lintels replaced with galvanised steel sections isolated from the masonry; stainless cavity ties installed across affected zones. Reinstatement and full repointing in analysed lime mortar, with a sample panel approved by the heritage consultant before proceeding. Cement-mortar patches removed and repointed correctly across both street elevations.
Outcome
Permit conditions discharged with full photographic documentation. The face brickwork reads as original because it is — every reclaimed unit went back where it came from.