Algae and lichen can flourish on roofs when there is a suitable amount of water and shade. They love aggregate surfaces that they can cling to, such as the surface of a roof tile. Both of them will spread across the roof over time if they are not tackled. This will harm the aesthetics of the property, but more importantly will have an impact on drainage, reducing the flow speed and efficiency of the tiles.

Generally algae is the first sign that your roof has the right conditions to encourage growth. This could be because of the shade, the type of tiles, or the closeness to trees and other plants. Each property will have a unique set of conditions so it is not uncommon to see one property with a roof covered with organic matter and a neighbouring property with a clean, fresh one.

Roofs covered in algae can quickly attract lichen too. The two have a symbiotic relationship with algae providing nourishment for the lichens and the latter providing protection so the other can grow. Ultimately it means that a roof can quickly get covered in a combination of the two.

If you are worried about the aesthetics or the disruption to water flows the news that both algae and lichen can be removed with simple cleaning will be well received. Crustose lichen is the trickiest to remove because it is tightly packed and forcibly attaches itself to the surface. Whether it is this type or foliose the material can be scraped from the tiles by using hand tools like rubber trowels or wire brushes.

This kind of cleaning is the best for the surface and keeps damage to the tiles to a minimum. It is important to keep in mind that in the process of the removal the grainy surface of each tile needs to be protected. Removing it will result in brittleness and dramatically cuts the lifecycle of the product. This is why pressure washing should be avoided.

As a team of experienced roof cleaners covering the Surrey area, we have extensive experience removing all types of algae, lichen and more destructive moss from roofs. We use hand tools to accomplish the removal of unwanted materials and then add a biocide to the surface for additional protection. When you are working with us you can look forward to a fresh looking, well presented roof.