Soft Washing in Rozelle

Rozelle's walls record how the suburb was built. From the 1850s Booth's Saw Mill on White Bay turned out cheap timber and weatherboards, and timber stayed the standard for workers' homes until brick terraces took over late in the century. Council notes that weatherboard buildings in The Valley include timber terraces that are now rare. Along the Iron Cove side, plastered brick is generally pre-1890 and face brick generally later, with the occasional stone cottage among them.

Each of those surfaces reacts to water differently. Old render can be soft and loosely bonded, weatherboard has painted laps and joints that a strong jet can force water into, and face brick depends on mortar joints that high pressure can erode. The Iron Cove, Valley and Easton Park guidelines all say to keep original plaster and to avoid painting unplastered face brick, which leaves cleaning as the main way to refresh these walls and makes the method decisive.

The grime comes from a crowded setting. Nearer White Bay houses stand on the road alignment with few front gardens, and around Easton Park some buildings sit right at the footpath, so facades catch dirt from passing traffic at close range. Continuous building lines and narrow lots keep some walls shaded for much of the day, and that is where mould and algae settle in.

With neighbours so close on every side, low pressure has a further advantage over a high-pressure jet: less spray thrown towards the house next door.

The most practical outcome of a soft wash here is that it can spare you a paint job you were never meant to do. Face brick darkened by grime tempts owners towards a coat of paint, yet Rozelle's conservation-area guidelines advise against painting original face brick. A careful wash is the better route back towards the brick's own colour.

Render and plaster get the same benefit. Mould and algae are broken down by the solution rather than blasted off, which keeps the original plaster finish in place, and painted weatherboard is cleaned without the coating being peeled back at the laps. That can push a repaint, or a plaster repair, further down the list.

The value extends beyond single houses. Around a third of Rozelle's occupied dwellings are flats or apartments, usually strata titled, and strata buildings are part of the work alongside houses. A clean facade goes a long way towards how a block or a leased terrace presents to buyers and tenants.

The products are biodegradable and safe around gardens, pets and children, which matters when the only garden is a narrow front strip or a courtyard. Before-and-after photos of every job show exactly how much the walls were carrying.