Moss damage to your roof

A little moss is mostly cosmetic — but left to build up, it traps moisture and accelerates wear.

Is moss actually a problem?

Thin moss is largely cosmetic. The problem comes when it builds up: it holds water against the tiles, blocks gutters and valleys, and in winter the freeze–thaw cycle can crack tiles and lift them. Clumps washing into gutters cause overflows that then soak the fascias and walls.

Removing moss safely

Moss should be removed gently — brushing and scraping, not high-pressure jet washing, which strips the protective surface off tiles and forces water under them. Some roofers fit zinc or copper strips near the ridge; rainwater running off them inhibits regrowth.

When moss hides a bigger issue

Heavy moss often grows on roofs that are already aged or north-facing and damp. If tiles are cracking, the surface is crumbling, or the roof is decades old, moss removal is a sticking plaster — and it's worth getting the roof assessed for replacement.