Sandstone care in Bilgola Plateau

Bilgola Plateau sits on high ground at about 150 metres, between Bilgola Beach and Newport on the ocean side and Clareville on the Pittwater side. The area was once known as Mount Loftus, after the governor Lord Augustus Loftus. It is mainly residential: houses make up almost all recent sales, about nine in ten homes are owner-occupied, and the suburb has a primary school, Bilgola Plateau Public School, a small park and two small rows of shops. Streets such as Plateau Road, Argyle Street and Kanimbla Crescent run along and down from the ridge. On these blocks, sandstone is used for retaining walls on sloping lots, steps, driveway edging and paved outdoor areas.

Sitting high on the ridge, Bilgola Plateau gets less direct salt spray than the beachfront, though east-facing homes can still catch salt carried on strong onshore winds. The bigger influences are vegetation and slope. Bushland reserves and road verges here hold remnants of the Duffys Forest ecological community, and gardens are often well treed, so leaf litter, bark and gum nuts end up on paving and steps. Shaded stone stays damp and grows black mould, algae and lichen. Sloping blocks need retaining walls, and these often show seepage stains and moss where groundwater moves through them. Driveways that drop steeply from the street can become slippery when growth builds up after a wet season.

Planning rules for the plateau still come from the Pittwater LEP 2014, the plan Northern Beaches Council inherited when Pittwater Council merged into it. No conservation area covers the suburb as far as we could find, but a single house may still appear on the schedule by itself, so anyone planning repairs or repointing, as opposed to a clean, should look at the heritage schedule first. Stormwater from these streets ends up in the ocean or in Pittwater, and NSW environmental law treats letting anything other than rain into those drains as pollution. Our technicians therefore block off drain inlets and collect the wash water for disposal. In the handful of strata properties, shared stone is the owners corporation's responsibility.

Bilgola Plateau is roughly 55 to 60 minutes from Double Bay, via Pittwater Road and Barrenjoey Road, so we plan jobs here as full days. Most homes are houses with off-street parking, which makes access straightforward, though steep driveways mean we check where the vehicle can safely stand. Retaining walls and terraced gardens are cleaned from the top down, with bunding at each level. We protect lawns, garden beds and pool fences before applying any product. Shaded gardens are slow to dry, so we usually come back on another day to seal. Families get a clear timeline for when each area is rinsed, dry and safe for children and pets again.