Comber Roof Cleaning, Protecting Slate and Tile from Moss Damage

Yes. Moss holds water against the surface like a sponge, and that trapped damp works into the joints and under the edges of the tiles. Over a wet Northern Irish winter it freezes and thaws, lifting tiles and slates and letting water track underneath. Clearing it early is far cheaper than replacing cracked or slipped tiles later.

Yes. Softwashing runs at low pressure, closer to a garden hose than a jet wash. A biocidal treatment does the work of killing the moss and algae, not force, so slate, concrete and clay tiles are cleaned without any risk of cracking or dislodging them.

It can, and that is why we never do it. Tile makers like Marley and Wienerberger warn that high pressure strips the protective surface off tiles and can void the manufacturer warranty. The jets also force water under the tiles into the felt and timber. Softwashing avoids all of that.

Because the treatment kills the growth at the root rather than just knocking it off, a roof usually stays clear for several years rather than greening back over the next wet season. Roofs in heavy shade or under trees green up sooner, and we are happy to advise once we have seen yours.

It depends on the size and pitch of the roof, how much moss is on it and the access, so we give a clear fixed price after a free look. As a rule of thumb a professional clean costs around one to two per cent of what a full roof replacement would, while adding years to the life of the roof you already have.

Most homes are done in a single day. The moss is cleared and the roof treated in one visit, and because the biocide keeps working after we leave, any stubborn patches carry on dying back over the following weeks.

Yes. We never walk on your roof. Water always flows down the pitch exactly as rainfall does, so we treat and rinse from the edge and from our access equipment, which protects both the tiles and our team. We are fully insured with two million pounds of public liability cover.

Yes, and it makes sense to do them at the same time. Moss and debris washed off the roof often ends up in the gutters, so we clear and clean the gutters, fascias and soffits as part of the visit to leave the whole roofline looking right.

Usually not. For most homes we reach the roof safely from ground-level access equipment, so there is no scaffold cost and no days of hire to wait on. If a roof is unusually high or awkward we will tell you before any work starts.

Yes. We carry two million pounds of public liability insurance and are Safewash certified, City and Guilds qualified and COSHH certified. We have been cleaning exteriors across Northern Ireland since 2003.