Sandstone cleaning and sealing in Beacon Hill

Sandstone around Beacon Hill homes is usually as old as the house: retaining walls holding back the slope, front walls and letterbox piers, steps to the back garden, and paving around the house or pool. After sixty or so years it often carries a history of cleaning methods. Some walls show the pale, furry surface left by pressure washers; others have orange blooms from acid brick cleaners. Over that sit the usual biological layers: lichen on caps, mould on shaded faces, tannin from bushland trees. Our technicians identify both the dirt and any old damage before choosing a method, and trial it on a discreet area first so you see the result before committing.

Our cleaning relies on chemistry and time rather than force. Biocide is applied to kill growth at the root and left to dwell, then lifted with soft brushes. Rinsing is done with a broad, gentle spray, never a turbo tip. Where previous pressure damage has opened the surface, we use even lower pressure and more dwell time. Orange iron staining from earlier acid washing gets a separate treatment, tested on a small area because results vary. Leaves are cleared before stone is wetted, and all wash water is bunded and recovered, so none of it finds its way into the street drains.

Sealing helps stone that has been opened up by past harsh cleaning, because it slows dirt and water from entering the damaged surface. We use a breathable penetrating product, never a film-forming coating, so moisture inside can still escape. Paving, steps and wall caps that dry well are the usual candidates; retaining walls with damp soil behind them stay unsealed. On the hilltop we pick a still, dry day for sealing, since wind dries the product unevenly and carries dust onto it. Natural and enhancing samples are applied next to each other for you to compare, and the product and date are logged for future maintenance.