Which? Trusted Traders is working with the Sunday Times to help answer reader questions about their homes. 

Question of the month: Should I remove lichen from my roof tiles?

‘My roof tiles are covered in lichen. I have received conflicting advice about whether I should have it removed. One trader says to remove it with chemicals and scraping; another says removal and scraping will weaken the tiles and I will need to replace the roof if I go ahead. Which one is right?’

CB, Sutton Coldfield

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Our expert says

‘Under the Consumer Rights Act companies must exercise reasonable care and skill when carrying out the work and when advising you. If it doesn’t and you end up with shoddy service or damage to your roof as a result you may be able to claim compensation. For example, if a company recommends that the lichen can be removed by chemicals and scraping, and this causes damage to the tiles resulting in the roof needing to be replaced, you may be able to make a claim against the company for the cost of fixing the roof.

‘Watch out for rogue traders trying to upsell you unnecessary work. It is unlawful for a company or trader to claim that work is required when they know it isn’t, or to deliberately overemphasise how effective a treatment or service is going to be. So before you agree to any work being carried out you should seek advice from an independent body such as the National Federation of Roofing Contractors (NFRC) or Confederation of Roofing Contractors (CORC).

You need to get an independent surveyor to come and take a look at the roof to see if it needs cleaning and whether it can handle being cleaned'

‘Bodies/trade associations such as CORC or NFRC may have general advice on whether to clean a roof or not and what to clean it with, but the consumer really needs to get an independent surveyor to come and take a look at the roof to see if it needs cleaning and whether it can handle being cleaned. The trade association should be able to recommend someone. Anyone who provides advice to consumers should have professional liability insurance to protect themselves and the consumer from negligent or wrong advice.

‘Once you have decided on the most suitable course of action you should obtain three quotes from reputable companies. Look for personal recommendations from people you know and trust or use an endorsed service such as Which? Trusted Traders, which carries out rigorous checks on traders. It also offers access to an independent alternative dispute-resolution service in case you have issues with the work conducted that cannot be resolved through the trader’s complaints process.’

Philip Thomas, head of quality assurance, Which? Trusted Traders

Read also:

The benefits of using a Which? Trusted Trader

At Which?, we’ve been testing products and services for over 60 years. The Which? Trusted Trader logo is a sign of reputation and trust – it helps you choose the right trader for you and gives good traders the recognition they deserve.

Every trader hoping to become a Which? Trusted Trader must pass an assessment process carried out by our trading standards professionals. In part, the assessment involves a credit report, a look at customer references and a thorough examination of business and administrative procedures.

The Which? Trusted Traders scheme aims to raise the standard of the trade industry for consumers, setting a benchmark we expect all traders to meet before they can become endorsed.

For more details, check in with our guide covering FAQs for consumers.

Advice for traders – All the latest announcements and information from Which? Trusted Traders.