Professional Roof Cleaning & Moss Removal

Dublin's high rainfall, humid climate, and mature tree cover create ideal conditions for moss, algae, and lichen to take hold on residential roofs. Once growth establishes — typically within 5–8 years of installation — it traps moisture against the tiles 24/7. Concrete tiles lose their protective granular surface. Slate edges lift and crack. Clay tiles develop hairline fractures from freeze-thaw cycles during cold winters. Within a decade of neglect, you can be facing replacement-grade roof damage that costs €15,000–€30,000.

Beyond structural damage, untreated roofs cause downstream problems. Moss debris constantly washes into gutters, downpipes, and gulleys, causing overflow stains down facades and damp patches in interior ceilings. Dark moss patches absorb heat in summer, increasing attic temperatures by 5–10°C. A clean roof can genuinely improve a home's energy efficiency and reduce summer cooling needs.

Soft Wash vs Pressure Washing — Why It Matters

Pressure washing a roof is a rookie mistake — and we see the damage every week. High-pressure water strips the granular surface coating from concrete tiles (the UV-protective layer), lifts slate edges, and can force water under the tile lap directly into your loft. The roof looks great for 6 months, then catastrophically erodes within 2–3 years.

Modern professional roof cleaning uses soft-wash technique: a low-pressure (sub-100 PSI) application of professional sodium hypochlorite biocide. We apply it, walk away, and let nature do the work. Over the following 2–4 weeks, rain gradually washes away the dead moss, algae, and lichen. The roof slowly returns to its original colour — without a single high-pressure jet touching it. This is the technique used by every reputable roof cleaner in Dublin and across Europe.

When Is the Best Time to Clean a Roof in Dublin?

Spring (April–June) is ideal — biocide works fastest in mild, dry weather, and you get the full summer for natural rain washing. Autumn (September–October) also works well before winter sets in. Avoid mid-winter (December–February) when temperatures dip near freezing, as the biocide is less effective in cold conditions and runoff can refreeze.

We recommend professional roof cleaning every 2–3 years for most Dublin properties. North-facing or heavily-shaded roofs may need it more frequently. South-facing roofs with good sun exposure can stretch to every 3–4 years. Annual biocide top-up treatments are available and double the lifespan of a deep clean — typically €120–€180 for a top-up vs €380–€700 for a full restore.

Is Roof Cleaning Worth It Before Selling?

Absolutely — kerb appeal is the #1 selling factor for residential properties in Dublin. Estate agents across the city routinely recommend a roof clean before listing because the impact on first impressions is enormous. We've had homeowners report €5,000–€15,000 higher offers after a €400–€600 roof clean. The ROI is one of the best in property maintenance.