Concrete and Clay Tile Roof Cleaning Without Cracking a Single Tile
Concrete and clay tile roofs are built to last decades, but they have two quirks that make cleaning them a specialist job: they grow moss even faster than asphalt shingle, and they are brittle underfoot. Get either part wrong and you trade a mossy roof for a cracked one.
Here is how tile roofs are cleaned properly in our climate, and why it is never a job for a pressure washer or a general handyman.
Why tile grows moss so readily
Concrete and clay tile are porous and textured, which gives moss more to anchor into than a smooth shingle. On shaded or rural properties, constant moisture and organic dust settle into that texture and feed heavy growth. Left alone, moss lifts at the tile edges, traps water against the surface through winter, and clogs the valleys and gutters below.
That is why a tile roof can look fine from the driveway and be carpeted in moss when you see it from above.
Never high pressure, and never careless footwork
High pressure erodes the surface of tile, blows out the colour coat and voids most manufacturer warranties. And walking a tile roof wrong cracks tiles, the load has to be spread and placed where tiles are supported, using proper fall-arrest safety.
The correct method is to remove the bulk moss by hand and brush, then apply a biodegradable soft-wash treatment that kills the remaining growth and spores at the root. The rain rinses the dead material over the following weeks, and the roof keeps getting cleaner rather than dirtier.
How long it lasts and what it costs
Because soft washing kills moss at the root, most tile roofs stay clear for two to four years, and a light re-treatment every couple of seasons keeps rural and heavily shaded roofs ahead of it. Killing the growth rather than blasting it off is what makes the result last.
Tile roofs are quoted per property, size, pitch, access and how much moss has taken hold all matter, and large or rural roofs are often assessed from aerial imagery and photos. A free quote is the fastest way to a real number.