Roof Biocide Treatment

What a biocide actually does

Moss, algae and lichen spread by spores that settle into the texture of the tile. Even after a thorough hand clean, those spores remain. A biocide is a treatment that kills them on the surface, taking away the starting point for the next crop of growth.

It isn't a coating and it doesn't change how your roof looks. Its job is protective: buying time between cleans and keeping the roof clearer for longer than cleaning alone would.

Why it goes on after cleaning

Spraying biocide onto a thick cushion of moss wastes most of the product on the moss itself. The treatment works best on a roof that has already been cleared, so it reaches the tile surface where the spores sit.

That's why we treat biocide as the final stage of a roof clean, typically following manual moss removal and, where appropriate, a soft wash. It's ideal after a clean rather than a substitute for one.

Roofs that benefit most

Some roofs grow moss far faster than others. A biocide is most worthwhile where:

• An elevation faces north or sits in shade for most of the day
• Trees overhang the roof or drop leaves onto it
• The roof has been cleaned before and turned green again quickly
• Concrete tiles, whose texture holds spores well

Applied safely

The treatment is applied carefully and at low pressure, as part of the same visit as the clean. We take care around gutters, plants and surrounding surfaces, and leave the site tidy. If you have particular concerns about a pond, plants or pets, mention them when you ask for a quote and we'll talk them through.

Honest advice about whether you need it

Not every roof does. A sunny, exposed pitch with little growth may stay clean happily without treatment, and we'll tell you so. Where regrowth is likely, adding biocide to the clean is usually the most cost-effective way to protect what you've paid for.

For a free, no-obligation quote, call 07752 853583, message us on WhatsApp or use the form below. We work from Petersfield across Hampshire, Surrey and Sussex, including Liss and Emsworth, insured up to £5,000,000 public liability.

Keeping a treated roof in good shape

After treatment, the roof still benefits from a little attention. Keep gutters clear so water isn't held against the lower courses of tiles, and trim back branches that overhang the roof, since shade and falling leaves are what feed the next round of growth.

Glance at the shaded elevations once or twice a year. Early green patches are much easier to deal with than a full cushion of moss. Our roof maintenance schedule guide sets out a sensible routine through the seasons if you'd like something to follow.

If growth does start to return, get in touch and we'll tell you honestly whether it needs another clean, a further treatment or can simply be left for now.