Moss on the roof: should I leave, replace or clean?

We often get to hear myths about roofing in the course of our work, many of them without any actual proof or factual evidence behind them. One of the most frequently heard myths is that there’s no point cleaning roofing with moss or algae growing on it, either because  it’s believed they actually serve to strengthen the roofing, or because they cause so much harm that once they are present it means you need entirely new roofing. We’re happy to say that neither of these is the case.

It is understandable why people might think the presence of moss on a roof could strengthen it. By making it seem thicker than it is, the moss may seem like it’s providing an extra layer of insulation or protection against rain and the wind. However, in real terms, moisture is going to be trapped in the moss, and that’s going to add to the weight which it is placing on your tiles. Far from giving protection, moss on your roof actually leaves it at more risk of damage.

Following on from that last point, the other comment we have heard is that once moss has grown on a roof, there’s no way to combat it and the only option you have is to replace the slates and tiles. Again this is not true. Moss is unfortunately always going to be likely to grow on roofing, but that’s not to say you can’t combat it. Our biocide treatment delivers a very effective way of limiting regrowth, keeping your roof cleaner for longer. In cases where moss does grow or returns, having a regular cleaning plan usually means that you don’t need to replace the affected tiles.

Moss or other forms of growth on your roof do not add to the protection roofing provides. It also does not mean you need to have tiles or slates replaced. Just as is the case with any part of your home or building, regular cleaning is required to ensure the condition is maintained. If you need regular professional roof cleaning in the Surrey area, we are the team you can always rely on for excellent service.