Cleaning and maintaining brick, stone and block walls

The method for the removal of moss, algae or lichen from walls very much depends upon the the type of brick, age and general condition of the wall.

With all types of construction, the removal of moss, algae, lichen or just greening is most important, not just for the appearance of the wall but to maintain its structural strength and lifespan. Brick, stone and block walls are porous and uneven surfaces provide the perfect surface for the moss, algae, lichen to happily grow. Unfortunately, this growth will, over a period of time, cause damage to the wall by loosening mortar and brickwork, all of which will eventually result in costly repairs.

A vast majority of this damage can be avoided by following some simple steps and undertaking a small amount of general maintenance:



The surface should be brushed to remove any loose growth, dirt and dust. The wall should then be inspected for damaged areas such as loose mortar, damaged bricks or loose stones and any remedial works undertaken.

If the wall is covered by trees, shrubs or plants, it may help to cut these back slightly to allow more light onto the surface, as this will allow the area to dry more quickly; dampness will encourage fresh growth of moss.



Once the surface has been brushed you can use a surface cleaner to help you remove dirt and staining as well as atmospheric staining from industry or traffic. These are generally sprayed on to the surface then left to act before being rinsed. This rinsing can be with water and a brush, a hosepipe or with a pressure washer.

Once the treated area is dry, we advise the application of our pH neutral surface cleaner. This is designed to be applied to a dry surface and on a dry day. As it is slowly rinsed by rain it will help to keep the surface clean.

After both of these treatments, you can apply a water repellent sealer to the surface. This will provide long term protection to the area for up to 10 years, as well as protecting against water ingress (which will reduce the effect of frost on both the bricks and mortar) and against dirt and general weathering. For these surfaces we recommend ROOF & WALL SEALER - Hydrosil BS. This is water based and soaks into the surface but still allows it to breathe.