Retrofitting Vapour Control: What If You Forgot It?

When it comes to airtightness and moisture management, vapour control is non-negotiable. But what if you’ve already completed your build or retrofit project and realise that you forgot to include it? The good news—it’s not too late. Intelligent Membranes offers liquid-applied solutions that make retrofitting vapour control simple, effective, and compliant with high-performance standards like Passivhaus.

Can You Retrofit Vapour Control?

Yes—you absolutely can. Traditional membranes often require stripping back finishes, causing mess, delays, and unnecessary costs. With Passive Purple, our liquid-applied airtight and vapour control layer, you can retrofit without compromise.

• Unfinished walls (plasterboard): Apply Passive Purple directly to the plasterboard. Then roll on Supergrip, and finally skim with plaster for a fully seamless, invisible solution.
• Already plastered surfaces: Roll on Airtight White. It’s quick, clean, and delivers the airtightness and vapour control performance you need.
• Want a different finish? No problem—Airtight White can be painted over with your chosen colour or finish, keeping design flexibility intact.

Why Liquid-Applied Vapour Control Works Best

Unlike sheets or tapes that can fail at junctions, Passive Purple and Airtight White flow into every crack, joint, and service penetration—securing areas that traditional methods miss. This ensures:

• Seamless coverage across irregular surfaces
• Improved airtightness test results
• Moisture management that protects building fabric
• Long-term performance that supports low-energy standards like Passivhaus retrofit

Retrofit Without the Headache

Whether you’re tackling a new retrofit project or correcting missed steps on an existing one, Intelligent Membranes’ vapour control solutions give you the flexibility to fix problems fast—without tearing buildings apart.

So, if you’ve asked yourself, “Forgot the vapour control—can I still do it?” The answer is simple: Yes, with Passive Purple, Airtight White, and Supergrip.

👉 Contact us today via our contact page to talk about how we can help retrofit vapour control into your project.