The NFRC (National Federation of Roofing Contractors) recently released a statement about removing roof moss and roof paints.
They advise homeowners to be cautous when dealing with companies that make claims about thermal coatings and possible damage caused by roof moss:
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 statement also questions claims about thermal roof coatings:
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.
The NFRC has also stated that moss growth on roof tiles is rarely a problem and should only be removed if it is blocking gutters and drainage outlets. You can read their advice here.
This advice only confirms the information we have been providing on this website, that moss does not damage roof tiles and using a pressure washer can damage roof tiles and push water into the roof space.
The NFRC was established over 120 years ago and is only the latest reputable body to warn about roof coatings and pressure washing roofs. See what the UK Trading Standards has to say here.
Have you read my article called 6 Roof Coating Myths Debunked?