Problem
A significant interwar brick apartment building presented stepped cracking over the window heads to the street elevation, consistent with lintel jacking, in which corroding steel lintels expand and lift the masonry above. A previous repair had repointed the cracks in hard cement mortar. This concealed the progression of the defect and damaged the brick arrises.
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 with the heritage consultant to support the owners corporation’s heritage permit application.
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 were discharged with full photographic documentation. Every reclaimed brick was reinstated in its original position, and the completed elevation retains its original fabric.