Moss on a Portsmouth 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 PO postcode across Portsmouth and the wider Hampshire. Roofs round here see salty south-coast humidity year-round, and most of the properties we treat are built with Welsh slate, clay plain tiles and concrete interlocking — so we tune the soft-wash mix and dwell time to whatever's on your ridge.
Most of the roofs we treat around Portsmouth are built with Welsh slate, clay plain tiles and concrete interlocking. 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 Portsmouth 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 Portsmouth.
Professional biocide applied at low pressure. It kills moss, algae and lichen at the root and keeps working for months — important given the salty south-coast humidity year-round.
Gutters cleared, downpipes flushed, debris bagged and taken away. Included on every Portsmouth 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: salty south-coast humidity year-round. 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 Portsmouth, the combination of Welsh slate, clay plain tiles and concrete interlocking and Hampshire'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 PO postcode across Hampshire.
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 use a professional, fully biodegradable biocide. We mask off planting where needed and flush gutters and downpipes once we're finished.
Most Portsmouth jobs are priced from the ground after a free roof inspection — pitch, access and tile type matter far more than property size. You'll get a written, fixed-price quote with no obligation.
After a full scrape, soft-wash and biocide treatment, most roofs in Portsmouth stay visibly clear for several years. An optional annual top-up biocide stretches that further.
Yes — we clear gutters, test downpipes and bag the debris on every Portsmouth roof clean. It's included, not an upsell.