Passive Purple

The world’s most airtight liquid-applied vapour control membrane.


Passive Purple airtight liquid-applied vapour control membrane - airtight paint
airtight vapour control

Why Choose Passive Purple


Passive Purple is a fully BBA certified Liquid Airtight Vapour Control Layer


Passive Purple offers you a perfect Radon Barrier to eliminate those nasty radon gases entering your building

up to 300m2 coverage a day

A single installer can apply up to 300m2 of Passive Purple a day using an airless spray device. This speeds up the construction time and dramatically cuts labour costs

Passivhaus Certified

Passive Purple is a certified Passivhaus component


Passive Purple is an M1 class, VOC-free water-based product. Zero nasty chemicals make it friendly for the user and the environment


Passive Purple is rated Fire Class C, unlike paper membranes which are rated Fire Class E

0.6ACH or under

With a Passivhaus certified score of 0.03ach (20x lower than the required 0.6ach) Passive Purple can guarantee you a score of 0.6ach (air changes per hour) and under. Whether you’re trying to achieve certified Passivhaus or just build to a Passivhaus standard, Passive Purple is your answer!

How to install

A closer look on how to install Passive Purple
Passive Purple

Why use us? The Passive low down!

We know what you’re thinking. Is it a nasty chemical? Well, No!! Passive Purple is a VOC-free water-based product. It’s completely free of any nasty chemicals or fumes… What’s more, as a water-based product, cleaning your paintbrushes and airless spray device is a smooth, no mess task.

Passive Purple adheres to any form of construction, allowing you to achieve maximum results for your desired goal. Once dry, Passive Purple forms an extremely tough yet flexible polymer membrane allowing it to move with the building settlement while also being super effective against impact damage. Passive Purple eliminates the inevitable rips, tears, unstuck tapes, staple holes, and many repairs you would expect to find on the classic paper membranes.

We have eradicated the need for paper, tapes and staples through this product, which eliminates all the problems that came with it (labour time, large quantity of damage repairs and waste material).

Passive Purple saves you money and delivers well above your goals.

Envelope Areas 

Passive Purple Liquid Airtight Vapour Control Membrane is an airtight coating that is spray applied with an airless spray device. It is designed to cover all areas of an external envelope (warm side of the insulation) of a building, including difficult connections in floors, walls, roofs 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 surface material where you apply Passive Purple needs to 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 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 with an airless paint spray 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. In this case, an airless spray device is not needed.

The wall/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/concrete or steel/concrete. Different construction materials react differently to changes in humidity and temperature, moving at different rates, which can lead to small cracks in plaster or another type of finishing. That movement can create air leaks that cause your building’s energy performance to suffer and potentially open the gateway for damp and mould to appear.

Both products can be used for these wall/ceiling connections: Passive Purple can be applied with an airless paint spray device. Or Passive Purple Brush can be applied by brush. 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 gets the job done.

Standard details
liquid membrane -Fluid membrane

Select your currency
GBP Pound sterling
EUR Euro


Here at Intelligent Membranes we are always looking for charities and foundations to support. Particularly this year, charities and foundations are among those truly impacted by the lack of funding. This is why we have created the Phuck Off Cancer version of our ‘Phuck Off’ product range and will be donating 100% of the profits from every tub sold! Please take a photo of your ‘Pink Ribbon’ face mask for social media and #Pinkribbonfoundation and #intelligentcommunity.

This website uses cookies to ensure you get the best experience on our website.