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Building Facades

All buildings in the UK are frequently exposed to damp, wet, and windy weather conditions. In addition to erosion and weather damage, this consistently damp weather can encourage the growth of moss or algae, particularly on older buildings or those constructed from stonework or cladding.

Algae and moss thrive in damp conditions, but also like to have a lot of light, meaning the flat external surfaces of buildings are perfect habitats for them to spread in ideal conditions. They can grow in large patches or films across a buildings surface with no defined borders, which are usually green, but can occasionally be black, red, or yellow.

 In addition to leaving stains on masonry and brick work, the expanding and contracting of algae and moss slime when it goes from wet to dry, can cause superficial damage to the stone surface. If the plant growth is thick, it can even create its own habitat for woody plants which can pose a danger of dislodging brick and stone with their roots.

Power washing is one option to ‘blast’ away the algae layer covering most surfaces, however, the water might not always be able to penetrate the smallest crevices on brick and stone work, leading to a quick repopulation. The power of the water jet also poses a risk of loosening the bricks or cement, causing a weakness, especially in older or historical buildings.

Some organisations recommend harsh cleaning agents such as bleach but  these can also cause damage to the building facade, especially in older and historic buildings.   We recommend purpose build products such as our very own Alage FREE product (link) and application by experienced cleaners who understand the different types of surfaces and the respective cleaning techniques for the best results.

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K Rend Cleaning and Algae Removal at Garnteg Primary School

Case Study Image - K Rend Cleaning and Algae Removal at Garnteg Primary School

The client’s school building was in a very bad state with over 15 years of red and black algae growth, moss, lichen build up and staining which was very off putting to new potential children and parents wishing to come to the school. The school had an excellent record for teaching and a fantastic range of facilities, but the external façade was in need of attention. The local authority called APT after the head of the school requested help to find an algae removal solution or to enhance the visual impact of the school.