Roof Cleaning North Shore | Moss, Lichen & Canopy Debris on Terracotta and Tile

Nowhere in Sydney grows moss on a roof like the North Shore. Full canopy shade, high humidity in the gullies, and litter constantly composting on the tiles give moss and lichen everything they need — and the terracotta rooflines through Roseville, Lindfield, Killara, Pymble, Turramurra and Wahroonga show it. The southern pitch of a canopy-covered Federation roof can carry a full moss mat within a few years of its last clean.

Moss is a water problem before it’s an appearance problem

A moss mat holds water against the tile permanently and wicks it up under the tile laps — which is how a sound roof starts leaking without a single cracked tile. It also blocks the water path down the roof, pushing flow sideways into valleys and behind flashings. Killing the moss properly is roof maintenance, not cosmetics.

Why we don’t blast it off

Pressure stripping takes the moss and the tile’s surface with it. Glazed terracotta — the signature roof of the Upper North Shore — loses its fired glaze to abrasive cleaning and never gets it back; the crazed, dulled surface that’s left holds moisture and regrows biology faster. Concrete tiles lose their colour coat. And on a brittle 100-year-old roof, careless pressure work and careless footwork crack tiles that then have to be found and replaced. Our roof cleaning treats the growth chemically, kills it through the root, and lets it die back and weather off — rinsing only where needed, at pressures the tile will carry.

Slate and heritage roofs

The slate roofs on the grander homes through Mosman, Killara and Wahroonga are the most fragile surfaces we work on — soft, layered stone that cracks under both pressure and foot traffic. These are slow, careful, chemical-first jobs with weight properly distributed, and we’d rather decline a shortcut than create a repair bill.

Ridge capping and valleys

High pressure blows lime bedding and pointing out from under ridge capping — the most common way a cheap roof clean becomes a leak. Capping and flashings are worked around, and the valleys, which on complex Federation rooflines are numerous and hidden from the ground, are cleared of the composted litter that blocks them. A blocked valley sends water sideways under the tiles and into the ceiling cavity silently.

What we photograph and report

Cracked, slipped and delaminating tiles, failed pointing, corroded valley irons, rusted gutter sections, damaged flashings. Photographed and sent through with the job — we don’t do the repairs, so you get an honest picture and decide what to act on.

Timing and pairing

Every two to three years for most canopy-covered roofs, sooner directly under large gums or liquidambars. Almost always booked with gutter cleaning — the dying moss ends up in the gutters, and doing both in one visit is the only sensible sequence. If the roof is growing moss, the shaded walls below are usually growing mould too: see house washing North Shore.

Fully insured with $20m public liability, correct height-safety equipment for steep and split-level blocks, fixed written quotes. Request a quote and we’ll respond within 24 hours.