Sandstone care on Collaroy Plateau

Collaroy Plateau takes its name from the steamer Collaroy, which ran aground on Long Reef in 1881, and it looks out over Collaroy, Long Reef and Narrabeen beaches and Narrabeen Lagoon. Its history includes a wartime radar station at Plateau Park, where Joseph Pawsey made Australia's first successful detection of solar radio waves in 1945. The Edgar Gornall Wildflower Garden, Anzac Avenue Reserve and Vic Huxley Oval add green space, and Plateau Road, Hall Avenue and Stella Street are among its residential streets. The native vegetation is shrubby dry sclerophyll forest on sandy, low-fertility soils. Homes are mostly houses, and sandstone appears in retaining walls, steps, terraces and pool surrounds.

On the Plateau, the stone problems come from height, bush and slope rather than surf. Wind across the high ground carries grit and dries exposed stone quickly, but lichen thrives on sunny caps and outcrops. Gardens near the wildflower garden and reserves collect leaves, bark and flower debris that stain paving brown. Blocks falling away toward the coast need retaining walls, and those walls hold damp soil behind them, so their faces stay wet and grow algae and moss. South-facing steps and side passages can spend most of the day in shade. East-facing terraces may pick up a light salt film on strong onshore days, but far less than stone at beach level.

We found no heritage conservation area on Collaroy Plateau. A Sydney Water reservoir here was once a listed item but was demolished in 2018, and the trig station on its site remains. For your own property, the Warringah LEP 2011 schedule of heritage items, or a call to council, will settle whether it is listed before older stonework is restored. Clause 5.10 generally requires consent for works to a listed item, although council may agree in writing that minor maintenance needs none. Most homes here are freestanding, but any townhouse group with shared paths and walls needs its owners corporation to approve common-property work. Wash water is recovered on every job, because the drains lead downhill to the beaches and lagoon.

Collaroy Plateau is a 40 to 50 minute run from Double Bay off-peak, as we estimate it, via the Spit Bridge and Pittwater Road. Many streets are steep and some driveways are too, so our technicians check vehicle access and how far equipment must be carried. Sloping gardens are worked from the top level down, with bunding and wet-vacuum recovery on each terrace. Leaf litter is cleared before stone is wetted, and plants near bush reserves are protected. On the higher, exposed blocks we choose a still day for sealing so wind does not dry the product unevenly. Walls in heavy shade can need an extra day or two of drying first.