Moss on a Cardiff roof isn't just cosmetic — it lifts tiles, blocks gutters and shortens the life of the whole roof. We clear it the safe way and treat it so it doesn't grow back. We cover every CF postcode across Cardiff and the wider South Wales. Roofs round here see mild, damp coastal weather that keeps roofs green for most of the year, and most of the properties we treat are built with Welsh slate, Bridgend clay and modern concrete tiles — so we tune the soft-wash mix and dwell time to whatever's on your ridge.
Most of the roofs we treat around Cardiff are built with Welsh slate, Bridgend clay and modern concrete tiles. Each tile type needs a slightly different approach — concrete tiles need a gentler biocide dwell time than slate, and pantiles need careful scraping in the lap. Here's what's included on a typical Cardiff job:
Every tile cleared by hand from a roof ladder or scaffold tower — no pressure washers, no broken tiles. The right approach for the older roofs you see across Cardiff.
Professional biocide applied at low pressure. It kills moss, algae and lichen at the root and keeps working for months — important given the mild, damp coastal weather that keeps roofs green for most of the year.
Gutters cleared, downpipes flushed, debris bagged and taken away. Included on every Cardiff roof clean.
Photos of every slope, ridge and valley. You'll see exactly what's on your roof before we quote — no pressure.
We re-bed loose ridge tiles and flag failing pointing while we're up there. Small fixes done on the day; bigger ones quoted separately.
Optional annual top-up applied from the ground. Stretches results from "several years" to "indefinitely" with minimal cost.
The short answer: mild, damp coastal weather that keeps roofs green for most of the year. Moss spores are airborne almost year-round, and any roof slope that stays damp for long periods will start to colonise — usually on the north-facing pitch first, then under any overhanging trees.
Around Cardiff, the combination of Welsh slate, Bridgend clay and modern concrete tiles and South Wales's climate means most roofs need attention every 3-5 years if they've never been treated, and far less often once a biocide programme is in place.
Left untreated, moss holds water against the tile surface, freezes and thaws through winter, lifts the lap, and eventually pushes debris into the gutter line. That's when small problems become roof-replacement problems.
Plus every CF postcode across South Wales.
Never. High-pressure water strips the protective coating off concrete tiles and forces water under slate. We hand-scrape and soft-wash only — that's the only safe way to clean a roof.
Yes. We clean carefully around PV panels and mounting brackets and avoid running biocide over the cells.
Without a biocide treatment, yes — usually within 12-18 months. The biocide is what kills spores at the root and keeps the roof clear long after we leave.
Yes, as long as it's dry and safe to access. Autumn and winter are actually peak season for treating moss — the biocide goes on before spring growth kicks off.
No — all the work is carried out outside. Just tell us about parking, side-gate access, pets and any solar panels before we arrive.