Passive Purple is the one stop shop for all your air tightness needs.

1. Envelope areas 

Passive Purple Liquid is an airtight coating which is sprayed with an airless spray device on all areas of an external envelope of a building including them difficult connection floor, wall ,roof and joist areas .As long as Passive Purple is used on the warm side of the insulation Passive Purple can be applied to either face of the external envelope.

  The material to have Passive purple applied on  must be 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 the Fibre version of Passive Purple.

After these preparations, Passive Purple Liquid can be sprayed with an airless paintspray device; this fast application method allows a single operative to apply up to 300 m2 per day.

For small projects, such as private houses, Passive Purple Brush can be used with a flat paintbrush, suitable for waterbased products. In this case, an airless spray device is not needed. Apply in two layers, with an interlap of 24 hours.

The wall/ceiling connections also need to be made airtight, certainly when the connections are made of two different types of construction materials such as red brick/concrete or steel/concrete. Different construction materials react differently to changes in humidity,temperature and also move at different rates which can lead to small cracks in plaster or another type of finishing, and so creating air leaks that will cause the energy performance of your building to suffer and potentially opening the gateway damp and mould to appear .

For these wall/ceiling connections, both products can be used: Passive Purple which is sprayed with an airless paintspray device  (1 layer) or Passive Purple brush  which is applied with a paintbrush in two layers. If you dont have an airless sprayer but would still wish to install Passive Purple your self dont worry we have a roller version for you, it may take a bit longer but it still gets the job done. 

2. Envelope  penetrations

Pipe and wire penetrations can be the down fall of any airtightness testing. Passive Purple is applied around objects that break through any surface to the external envelope sealing where most tapes and membranes fail.  

Before you apply Passive Purple ,  first apply polyurethane foam around the any penetrations; after hardening, remove the excessive foam, and apply 2 layers of Passive Purple Brush with a flat paintbrush; in all cases, apply a sufficient, well covering layer to guarantee airtightness.

3. Window/Door reveals 

Passive Purple can be applied (and is tested) on different construction materials such as concrete, brick, wood,PVC, aluminium ,polyurethane foam and with two layers of Passive Purple , the whole window/door reveals can be made airtight.

Working method: cut off the excess of polyurethane foam, and apply Blowerproof Liquid Brush.

Regarding the protection of the window profiles, apply a protective tape at max. 5 mm from the side of the profile. This tape needs to be removed shortly after finishing the application of Passive Purple . The interlap between the 2 layers can be limited to 10-15 minutes.

Passive Purple / Airtight White Brush (5kg)

Passive Purple / Airtight White Brush (5kg)

BBA approved paint-on airtight Passive Purple/Airtight white coating is suited for the permanent airtightness of all building connections. With this one product, you reach a passive airtightness level of your house or building.

Christmas special offer


Passive Purple / Airtight White Spray/Roller (10kg)

Passive Purple / Airtight White Spray/Roller (10kg)

BBA approved spray/roller-on airtight Vapour control membrane coating which is suited for the permanent airtightness of all types of building envelopes and any form of construction .With this one product, you reach a passive airtightness levels for your house or building.


Isoproof Façade Spray Membrane (10kg)

Isoproof Façade Spray Membrane (10kg)

Isoproof is a external facade spray that is vapour open and gets rid of traditional tapes and membranes. Comes in black and grey colours.