• Why the "Parge Coat" is Failing You

    For decades, builders have relied on a "parge coat" (wet sand and cement render) to make blockwork airtight. But as we strive for Passivhaus standards, this old method is showing its cracks.

    1. The "Cracking" Problem
    A parge coat is rigid. As your new house settles and the blockwork shifts, the rigid plaster cannot handle the movement.

    • Result: It cracks.
    • The Failure: Even a hairline crack in your parge coat ruins your airtightness score. You can't see it behind the plasterboard, but the heat is leaking out.
    • The Fix:Passive Purple is flexible. It is a rubber-like membrane that stretches with the building's movement. It doesn't crack; it adapts.

    2. The "Joist End" Nightmare
    This is the #1 leak point in masonry builds. Where timber floor joists enter the block wall, a plasterer simply cannot get a seal.

    • The Failure: Timber shrinks. Plaster doesn't. A gap opens up around the joist, pumping cold air into your floor void.
    • The Fix: Passive Purple flows. You simply spray over the joist end and the wall in one pass. The liquid moulds perfectly to the timber and the block, creating a permanent, flexible seal that stays tight even when the wood shrinks.

  • How We Changed Passivhaus Building

    We have made airtightness faster, cleaner, and more reliable for traditional builders.

    • Penetrates & Seals: Concrete blocks are porous. Passive Purple penetrates deep into the pores of the block and the mortar, locking the surface down instantly.
    • The "Visual Check": With wet plaster, it’s hard to see missed spots. Passive Purple turns a vibrant purple, allowing you to visually verify that every mortar joint, corner, and joist end is sealed before you cover it up.
    • Speed: One operator can seal a whole house in a day. No trowels, no mixing, no waiting for plaster to dry.

  • Finishes: The"SuperGrip" System

    One of the biggest questions is: "If I seal the blockwork, how do I stick my plasterboard to it?"

    We have revolutionized that too. You don't need to build expensive timber stud walls inside your blockwork just to hold the insulation.

    1. Spray: Seal the blockwork (and joist ends) with Passive Purple.
    2. Prime: Apply Intelligent Membranes SuperGrip Primer. This adds a heavy, gritty texture to the surface.
    3. Dot & Dab: You can now apply standard drywall adhesive (dabs) directly to the wall and stick your plasterboard up as normal.

    Result: A Passivhaus-tight masonry wall, finished with standard drylining techniques

The "Radon Bonus"

We sell Passive Purple as the ultimate airtightness layer. But for blockwork builds, you get a massive free extra. It is a Certified Radon Barrier. By spraying your blockwork walls and the floor-to-wall junction, you are creating a seamless shield against ground gases—something a cracked parge coat can never guarantee.

Ready to Update Your Methods?

Stop relying on brittle, cracking plaster. Switch to the membrane that moves.

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