• The Radon Risk in Older Homes

    If you are renovating or extending an older property, you face unique challenges. As buildings settle over time, tiny cracks appear in the foundations and masonry. These are open doorways for Radon gas to seep from the ground into your living space.

    The Limitation of Ground Sheets
    While a traditional DPM (Damp Proof Membrane) or radon sump under the
    floor is essential, it isn't always enough—especially in retrofits where you
    can't easily access the foundations. Gas can still bypass these sheets through:

    • Wall-to-floor junctions.
    • Cracks in existing brickwork or concrete.
    • Service penetrations (pipes and wires).

    You need a second line of defence.

  • The "Belt and Braces" Solution

    Smart renovators take a "belt and braces" approach. They use Passive Purple to create a continuous, verified gas-tight seal from the inside.
    Passive Purple is primarily a world-class Liquid Airtight Vapour Control Layer designed to keep your home warm. But because it forms such a dense, impenetrable skin, it also acts as a powerful Certified Radon Barrier.

    Why it’s Perfect for Retrofit:

    1. Seals the Cracks: Old walls are never flat. Passive Purple is a liquid that flows into every hairline crack,
      mortar joint, and imperfection in your masonry, sealing leaks that sheets
      and tapes simply can't reach.
    2. The Junction Specialist: The most common entry point for Radon is where the floor meets the wall. Painting Passive Purple over this junction creates an unbreakable, flexible seal that moves with the building.
    3. Added Peace of Mind: Think of it as your safety net. If your primary ground sheet has a defect, Passive Purple is there to stop the gas before it enters your room.

  • How It Works

    1. Prep: Clean your existing walls (brick, block, or concrete) and fill any large gaps.
    2. Apply: Spray or brush Passive Purple over the surface, paying close attention to the floor perimeter.
    3. Dry: The liquid cures to a vibrant purple, rubber-like membrane. This visual indicator lets you see exactly where you are protected—no missed spots allowed.
    4. Result: You have a fully airtight home (saving you money on heating) that is also fortified against ground gases.

FAQ: Retrofit Radon Protection

Does this replace my Radon sump or ground sheet?

No. We recommend a "Belt and Braces" approach. Keep your primary ground
protection measures in place. Passive Purple acts as an additional, crucial
layer of defence on the warm side of the construction to catch any gas that
bypasses the primary measures.

I apply it directly to old brickwork?

Yes! Passive Purple adheres aggressively to masonry, concrete, and block. It is far superior to trying to tape plastic sheets to uneven old walls.

What about Airtightness?

That is actually its main job! By applying Passive Purple for Radon, you are automatically making your retrofit airtight. This stops drafts, reduces heat loss, and helps you achieve modern energy standards in an old home.

Upgrade Your Defences Today

Don't leave your renovation to chance. Lock out Radon and lock in the heat with the industry's leading liquid membrane.

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