Why moss is bad news for roofs

It is very common for roofs to attract plant life – particularly in shady areas underneath trees.  While lichens can add to the attractive aging patina of a roof, too much moss or other plants can cause your roof to leak.

The reason is that the roof is constructed to channel water down the surface to the gutter where it drains away.  The drainage occurs not only across the surface of the tiles, but also under the tiles where the underlay will also take water down to the gutter.

If any of these drainage channels are blocked – you can get a leaking roof. 

So if you notice a significant green bloom on your roof tiles you should eliminate it.    This is not something you should attempt yourself – get a reliable roofing contractor in to do the work.

Most importantly, you should never use high pressure water jets to clean the surface of the tiles as this pressure can easily damage or crack the tiles and cause more problems.

And once you’ve got rid of the moss the roof should be treated with an appropriate biocide to make sure it doesn’t come back.