Merchant Houses

Architects: Salmon Reed Architects

1880s vintage and Category 2 listed, 16 Symond Street is the middle of three Italianate mansions – the ‘Merchant Houses.’  Now used by the University as a public facility, its seismic rating of less that 33% of the New Building Standard (NBS) was unacceptable.

Features that contribute to the beauty and heritage value of the building – unreinforced masonry (URM), highly ornate ceilings and tongue-and-groove floors – were prime contributors to the earthquake hazard.  A non-intrusive method was required to tie these elements together.

We investigated an innovative approach to strengthening URM that involves a cement-like compound reinforced with synthetic fibres.  Trade named ‘Flexus,’ this is sprayed onto internal walls in place of the plaster – it proved effective and economic.

The floors needed to be tied in to the walls and major settlement cracks above door and window lintels rectified.  Grooves were cut into the masonry and steel reinforcing elements inserted –right-angled steel brackets to tie the floor in and steel reinforcing bars above lintels.  Everything, grooves, steel elements and associated walls, was then sprayed with Flexus.

The result is a 100% NBS building that retains its Victorian personality.