1. Moss on your roof Moss can shorten the life span of your roof and result in costly repairs or even the replacement of the roof coverings. Homeowners may think moss on roofs is just a cosmetic problem or even pretty. Yet leaving it in place can damage the roof and the timber components of the roof. Some of the problems caused by moss growth are detailed below for your reference; – Moss acts like a sponge, absorbing and storing large amounts of moisture and rainwater which causes the roof to be constantly wet. If the moisture travels beneath the roof covering, it could cause the timbers to the roof to corrode, resulting in both structural and cosmetic damage which could lead to costly repairs or even the replacement of the roof coverings. Should the wood roof sheathing become wet, it can readily cause mold growth and serious decay, this may cause the roof to lose its structural integrity and can become unsafe. The main benefit of a pitched roof is the easy drainage of water due to the sloped angle. However, moss can obstruct the path of the water by absorbing the moisture and water, causing the channels of the tiles to block preventing the water from draining from the roof. Moss can break off and fall into gutters or downpipes, blocking your drainage system which may cause internal water ingress. It is therefore advised, to have moss build removed from the roof which is usually carried out with a cleaning agent and a stiff broom to minimize damage occurring to the roof coverings, a low pressure washer can be used; however, this may cause damage to the coverings and could cause water to penetrate beneath the roof coverings.