Sandstone and travertine care in Sydney's Eastern Suburbs

The Eastern Suburbs sit on Hawkesbury sandstone, a Middle Triassic rock laid down roughly 247 to 242 million years ago. It is made almost entirely of quartz grains held together by clay, and when it was quarried as 'yellowblock' it weathered to the warm yellow-brown that marks so much of Sydney's nineteenth-century building. The region shows it at every scale: the Vaucluse House estate, Victoria Barracks in Paddington, the 1850s to 1870s villas of Randwick and the sandstone semis of Bronte, cut from quarries near Waverley Cemetery. Most properties here carry some of it, whether a garden wall, a flight of front steps, a sea wall or a pool coping, and nearly all of it is softer than it looks.

Exposure splits the region in two. Along the harbour, from Darling Point and Double Bay out through Point Piper, Rose Bay and Vaucluse, stone faces calmer water but still takes splash on sea walls, strong reflected sun and a steady load of airborne salt. On the ocean side, Dover Heights, Bondi, Tamarama, Bronte, Clovelly and Coogee face the open sea, and onshore wind carries spray well back from the cliff line. Research from the University of Technology Sydney names salt as one of the main enemies of Sydney sandstone in coastal areas. Salty water soaks into the pores, the water evaporates, and the crystals left behind push the grains apart. That is the flaking and white bloom most owners notice first.

Three councils cover most of the region, and each takes heritage seriously. Woollahra Council looks after the harbour suburbs and has 15 heritage conservation areas, including Paddington, rezoned in 1968 as Australia's first conservation area, plus large areas in Woollahra and Watsons Bay with their own planning chapters. Waverley Council lists 17 conservation areas, among them Busby Parade in Bronte and the Bondi Beach area along Campbell Parade. Randwick Council has 21, including the St Judes precinct in Randwick and the Dudley Street and Edgecumbe Estate areas in Coogee. The part of Paddington south of Oxford Street falls under the City of Sydney. If your home is a listed item or sits inside one of these areas, check with the relevant council before significant stone work begins.

The same problems turn up in predictable places. Shaded, south-facing retaining walls on the ridges of Bellevue Hill and Darling Point grow black mould and lichen. Old sandstone footings and front steps in Paddington, Woollahra and Randwick draw up ground moisture and bloom with salt. Pool coping on harbourfront and clifftop properties pits and turns sugary at the waterline. Travertine terraces get etched by acidic pool-shop cleaners, and sandstone gets scarred by pressure washers held too close. Our technicians answer each of these the same careful way: a test patch first, low pressure on sandstone, no acid on travertine, and breathable penetrating sealers. Wash water is captured on site rather than sent down the stormwater drain, which is meant for rainwater only.