Moss and algae on roofs — repair or just clean?
Moss on a roof isn't purely cosmetic — it can hold moisture against tiles and, over years, contribute to wear. Roof cleaning can help on an otherwise sound roof, but heavy moss on an older roof sometimes indicates it's simply due for replacement rather than cleaning being a lasting fix.
What affects the cost
Cost depends on roof size and pitch (steeper roofs need more scaffolding and take longer), the material (slate costs more than concrete tile), access, and whether the existing roof structure (timbers, felt) needs work too, not just the visible covering. A straightforward repair is quick; a full re-roof including scaffolding commonly takes 1-3 weeks.
What a roof survey actually checks
A proper roof survey looks beyond the visible tiles — timber condition in the loft, flashing around chimneys and valleys, ventilation, and signs of past repairs. Worth requesting one before buying a property with an older roof, since problems aren't always visible from ground level or even from inside the loft.
Common roofing myths, busted
"A few loose tiles are always urgent" — sometimes, but not always; a roofer can usually tell you if it can wait for a scheduled visit. "Moss means the roof needs replacing" — not necessarily, see roof cleaning above. "Flat roofs always leak eventually" — modern EPDM/rubber flat roofing lasts decades if properly installed.
Seasonal roof checks worth doing
Before winter: check for loose tiles and clear gutters, since blocked gutters and ice are a common combination for damage. After a storm: a visual check from the ground for obvious damage, before assuming everything's fine just because there's no visible leak yet.
Leadwork around chimneys and valleys
Lead flashing seals the joins where a roof meets a chimney, wall, or valley — a very common source of leaks when it perishes or is poorly installed, even if the roof tiles themselves are fine. If a leak keeps recurring in the same spot near a chimney, it's often the leadwork rather than the tiles that needs attention.
Conservation areas and roofing materials
Even without individual listing, a property in a conservation area can have restrictions on visible roofing changes — different tile colours, added skylights on street-facing slopes, or replacing natural slate with a synthetic alternative. Check with your local planning authority before ordering materials.
Roof insulation, where it goes
Loft insulation (laid flat, cheap, effective) is different from insulating the roof slope itself (needed if the loft is being converted into living space). A re-roof is often the most cost-effective time to upgrade roof-level insulation, since the covering is already off.