Passive Purple Liquid Airtight Vapour Control Membrane is an airtight coating that is applied with an airless spray device on all areas of an external envelope (warm side of the insulation) of a building. This includes those difficult connection areas to the floor, wall, roof and joist.When Passive Purple is used on the warm side of the insulation, it can be applied to either face of the external envelope. To install Passive Purple, you simply need to ensure the material or surface is dust-free, solid and closed before starting the application. A closed surface implies that holes and joints need to be closed beforehand: large holes and joints (> 5mm) can be closed with a fast setting cement-based products or polyurethane foam, small holes and joints (2-5mm) can be closed with Passive Purple Liquid Brush, this is a much thicker (paintbrush applied version of Passive Purple). After these preparations, Passive Purple can be sprayed on with an airless machine, allowing you to apply up to 300 m2 per day with a single operator. For small projects, such as private houses, Passive Purple Brush can be used with a flat paintbrush. The wall and ceiling connections also need to be made airtight, especially when the connections are made of two different types of construction materials such as red brick and concrete or steel and concrete. Different construction materials react differently to changes in humidity, temperature and move at different rates, which can lead to small cracks in plaster or another type of finishing. This can create air leaks that will cause the energy performance of your building to suffer and potentially opening the gateway for damp and mold to appear. Both airtight paints can be used for these wall to ceiling connections: Passive Purple spray-applied and Passive Purple brush. Note: If you don’t have an airless sprayer but would still wish to install Passive Purple yourself, don’t worry, we have a roller version for you. It may take a bit longer, but it still gets the job done. Passive Purple Internal is a Passive House High-performance building material.