Roof Cleaning in Willoughby

Willoughby sits about 97 metres above sea level on the central plateau of its local government area, and its ridge-top streets are on clay-loam soils that once carried Blue Gum High Forest. That forest was cleared in the 19th century for timber, small farms and orchards, then for housing, and the streets of the south-central precinct now carry planted street trees rather than remnant bush. Those plantings mix exotic and native species, with Brush Box, jacaranda and camphor laurel among them, so a plateau roof may sit under almost any of them.

The southern and south-eastern edge is different ground. Council's street tree plan describes moderate to very steep Hawkesbury sandstone slopes there, with outcrops, benches and broken scarps up to 10 metres high, dropping toward around 14 hectares of remnant bushland in Flat Rock Gully. A house beneath a scarp or backing onto the gully can lose much of its direct sun, and the shaded roof planes are the ones that tend to turn green and black with lichen and moss.

The climate keeps growth going year round, with humidity changing little between months and annual rainfall above 1,200 millimetres. Terracotta, concrete tile and metal each need their own approach; even the 1930s Walter Burley Griffin Incinerator on Small Street is roofed in green concrete tiles. After the inspection we choose between a soft wash and controlled pressure cleaning to suit the surface, then apply an anti-mould and lichen treatment to slow regrowth.

Willoughby City has twelve Heritage Conservation Areas, among them the Willoughby Park area around Fourth Avenue, McClelland Street and Warrane Road, whose key period runs from 1907 to 1930. Council's guidance is that maintenance and repairs introducing no new materials, such as replacing roof tiles with matching tiles, do not need a development application. Switching to a different roofing material falls outside that description.

That makes cleaning the practical way to keep an older roof in service. Lichen roots into the surface of aged terracotta and holds moisture against it, while moss packed along the tile laps slows the water that should be running to the gutter. Removing both, then treating the tiles to slow regrowth, helps the roof you already have stay in service, with any repairs kept to matching tiles.

Outside the conservation areas the case is simpler. A clean roof changes how a house reads from the street and in sale photography, and because an inspection comes first, cracked or slipped tiles can be pointed out while they are still a small fix.

You receive before-and-after photos of the roof, so the result can be seen without anyone in the household climbing a ladder.