Algae — The Ringleader
Red and Green algae are in charge! When people notice staining on their walls, it is often the red colour that draws attention first. It stands out. It looks unusual. It raises concern. But red algae is only part of the picture. Green algae is just as important — and often more widespread. What is […]
The Usual Suspects:
What Is Really Growing on Your Walls Most people assume the staining on exterior walls is dirt, pollution, or general weathering. In reality, it is usually a living layer of biological growth. This layer is made up of four main organisms: Together, they form what is known as biomass growth. It starts with algae Algae […]
Exterior Treatment of Historic Buildings: What You Need to Know
Over recent weeks, we have explored the subject of exterior treatment from several perspectives: industry practice, material behaviour, biological growth and chemical selection. Taken together, these discussions point to a simple conclusion. Exterior treatment of historic buildings is not a routine cleaning task.It is a conservation intervention. This final article sets out the key considerations […]
What Does Responsible Exterior Treatment Look Like?
Over the course of this series, several themes have emerged. Exterior treatment remains a largely unregulated activity.Methods and materials vary significantly.The consequences of inappropriate intervention are not always immediately visible. The final question, therefore, is a constructive one. What does responsible exterior treatment actually look like? Understanding the material Historic buildings are composed of materials […]
Exterior Treatment and Professional Competence: Why Standards Matter
Exterior treatment work sits in a curious position within the built environment sector. On one hand, it involves direct intervention in historic and modern fabric — stone, lime render, slate, timber, lead, glazing and delicate architectural detail. On the other, it remains largely unregulated. There are no universally recognised competency thresholds, no mandatory accreditation […]