Sandstone cleaning and sealing in Narrabeen

In Narrabeen, the sandstone our technicians see most is in apartment buildings along Pittwater Road and the streets leading to the beach and lagoon. Entry steps carry the heaviest load: sand tracked up from the beach, spilled coffee, chewing gum and a dark wear path down the centre of each tread. Front walls collect grime from passing traffic, and shaded side paths near the bin area go green or black. Lagoon-side houses have a different set of problems, mostly growth on garden edging and stepping stones. We note each of these on a site walk, then trial our cleaner and dwell time on a small, out-of-the-way section before committing to the whole area.

The clean itself is deliberately slow. Organic growth is sprayed with a stone-safe biocide and given enough time to kill it right down to the roots. Gum is softened and lifted rather than scraped. Grease and food marks near entries get a targeted degreaser, and if they have soaked deep, a poultice draws them out over a day or two. Rinsing is done at low pressure, working downhill from the top step, while a wet vacuum collects water at the bottom. In a strata building we close off half the width of a stair at a time so people living there always have a way through, and signage stays up until each part is dry.

Sealing a shared entry is mainly about making the stone easier to keep clean. A breathable penetrating sealer reduces how quickly spills and salty water soak in, yet leaves the surface texture alone, so grip on wet steps is not reduced. We do not put glossy coatings on stairs. Front walls retaining soil generally stay unsealed, because damp needs a way out through the face. For the owners corporation, which is responsible for maintaining common property under section 106 of the strata legislation, we provide a written record of the products used, the areas treated and a suggested inspection date. Most Narrabeen entries benefit from a check every year or two.