Roof cleaning, moss removal & maintenance in Macclesfield

Moss is not, in itself, an emergency, and anybody telling you otherwise on your doorstep is selling. What moss actually does is hold water against the covering, which matters on a porous concrete tile in a frost pocket, and it breaks off and blocks the gutters, which matters everywhere. On a sound slate roof it is largely cosmetic.

How it is removed matters far more than whether it is removed. A pressure washer on a roof is one of the most damaging things that can be done to it: it strips the granular surface off concrete tiles, drives water under the laps and into the roof space, and shortens the life of the covering it is supposedly protecting. Scraping and brushing by hand, then treating with a biocide and letting the weather take the residue, is slower and correct.

The maintenance that genuinely pays is unglamorous: gutters cleared before winter, a look at the flashings and the stack once a year, valleys kept free, and any slipped slate dealt with while it is still one slate. On a house with trees over it that is an annual job; on an exposed roof with nothing overhanging, every two or three years is honest.

The other half of maintenance is knowing when to leave it alone. Roof coatings and 'sealants' sprayed over an old tiled roof are widely sold and rarely a good idea — they trap moisture, they can void a survey, and they make the roof harder to repair afterwards. If a roof needs replacing, a coating does not replace it.