Roof Cleaning & Moss Removal

A pitched roof is designed to shed rain down overlapping tiles. It is not built for a powerful jet of water directed at close range. Removing moss and debris manually gives us more control around tiles, ridges, flashings and other roof details. We can work in sections, check the condition of the covering as we go and identify any loose or damaged tiles that need separate attention.

Manual cleaning still needs care. A scraper or brush used too aggressively can mark or damage tiles, so we assess the tile type, its condition and safe access before recommending a method. The aim is to remove unwanted build-up without compromising the roof beneath it. Tile manufacturer Wienerberger describes hand removal with a suitable tool or brush as one approach to moss cleaning.

A high-pressure washer can make a roof look cleaner quickly, but the force that removes moss can also crack or damage tiles and wear away their finish. On some concrete tiles it can strip colour from the surface. Water may be driven into the overlaps between tiles, which are intended to shed rainfall travelling down the slope rather than resist water forced upwards or sideways. Moss and debris can also be pushed into roof details and drainage outlets. Older or fragile coverings need particular care.

Roof tile manufacturers warn about these risks. Marley advises against pressure washing clay tiles and concrete tiles, citing possible tile damage and water entering the roof structure. Wienerberger advises avoiding high-pressure jet washing because it can damage tile finishes and force water beneath tile overlaps.

That does not mean every form of water cleaning is unsuitable. Wienerberger sets out precautions for a low-pressure wash in some circumstances. The right choice depends on the roof covering, condition and manufacturer guidance. We assess those factors first rather than promise the same process for every property.