Are you Worried about Moss on your Roof?

While NFRC is a dedicated roofing trade association that has been around for over 130 years we have never recognised the practice of moss removal or roof painting as a true roofing discipline. The reason being, in most instances, moss on roof tiles is rarely a problem and only needs to be removed if it is blocking gutters, outlets and other drainage points on the roof. Most ‘techniques’ that we have come across to remove moss, are often achieved by ‘violent’ means such as power-washing, which may cause damage to the roof, especially when combined with unnecessary foot traffic often leading to cracked or broken roof tiles.

The principal cause for the growth of mosses and lichens on pitched roofs is their rough surface, which filters dirt out of rainwater. Decaying matter, in the form of dead leaves which fall on to the roof, also tend to lodge on the surface. Spores and seeds of mosses and lichens are also blown on to the roof, taking root and growing in the dirt. Inevitably, the surface of some concrete tiles, with a sanded or granule facing, are the first to attract moss growth.

The removal of the moss is often followed up by painting the roof tiles. There are claims that this can increase the thermal efficiency of roofs as well as extending the life of the roof tiles, but unless the products carry credible UK based, third party accreditation we would urge members of the public to view any claims with extreme caution.

Our advice, therefore, to property owners who are concerned about the condition of their roof is to contact a reputable roofing contractor for a proper assessment and, if necessary, to obtain at least three quotes for any works, using conventional roofing methods. To find a local roofing contractor you may use our directory.

For additional advice, refer to our Guidance Note.

A further piece of advice for members of the public especially those who are concerned for elderly relatives who could be subject to doorstep selling, is to go to Citizens Advice for free advice on handling doorstep sellers.