Sustainable composite materials for building surface maintenance

Lead Participant: Pennog Limited

Reductions in the toxicity and acidity of rain as a result of the Clean Air Act (1968) led to an uncontrolled proliferation of lichen and algae on surfaced in the built environment. Algae can cause unsightly staining of building surfaces. Lichen, which are a symbiotic relationship between algae and fungi, provide an anchorage point and nutrient source for moss on roofs. Moss growth on roofs block drainage channels and freeze and expand in winter, pushing slates apart leading to water ingress into roof spaces and losses of thermal integrity.

The roof moss cleaning industry currently uses environmentally damaging algaecide sprays to prevent lichen and moss re-growth. A process that needs to be repeated every 2-3 years. Copper wire, bands and ridge tiles, which oxidise and release copper over a roof surface provide a more environmentally-benign alternative for moss control. However, copper surfaces oxidise rapidly and require roof access for abrasive polishing every 2-3 years to continue working.

In a previous Innovate UK project the project partners created composite materials composed predominantly of by-products from food and drink manufacturing industries, that could provide up to 15 years of maintenance-free control of algae, lichen and moss growth on a range of surfaces in the built environment. The wider benefits of this technology are a reduced use of organic biocide pollutants, a reduction in cost and potential roof damage risk for householders and use of non-renewable resources use and the re-purposing of waste materials. This project will identify and address the economic and technological challenges for introducing an innovative solution to further enhance environmental sustainability and a Circular Economy business model for commercialising the innovation.