Sandstone cleaning and sealing in South Coogee

Near the cliffs, South Coogee sandstone is usually garden walls, terraced stairs and paving that catch spray from Lurline Bay. You can often see a crust on the seaward face, loose sand at the foot of walls, and stairs that turn green in winter where they never get sun. Back toward Malabar Road, unit blocks have sandstone fences, piers and entry steps grey with grime and sometimes marked by earlier pressure washing. We note which side of the problem each surface sits on, salt or growth or grime, and test a small area before quoting, because a single product rarely suits all three.

Salt comes off first, by dry brushing and vacuuming, then a fresh-water rinse at modest pressure; where it has soaked deep, a poultice pulls it out over a day or two. Shaded stairs and walls get a stone-safe biocide that is allowed to finish its work before rinsing. Grime on unit fences responds to a sandstone detergent and soft brushing. We do not use acid, and no concentrated jet touches the stone, since coastal sandstone that has been salt-loaded for years loses grains readily. Bunds and wet vacuums keep the water on site, so none of it heads down the slope to the cliff or the gutter.

Sealing in South Coogee suits the surfaces that take spray and traffic: terrace paving, stair treads and wall caps on the coast, entry steps and paths at the unit blocks. A breathable impregnator slows salt uptake and makes rinsing and sweeping more effective, while the stone can still dry from inside. Retaining walls with wet soil behind them stay unsealed. Samples of natural and enhancing finishes go down first so you can choose in daylight. We record the product and date, and suggest checking clifftop paving every year with a few drops of water, since ocean-facing protection wears faster than it does inland.