Airtight White: Fire Rated -Airtight & Vapour Control Membrane for Internal Applications - Spray-applied Airtight Liquid Membrane

Product Application – Passive Purple® Airtight White

General

Application to be carried out in accordance with the manufacturer’s written instructions.

The membrane shall be applied to form a continuous, uninterrupted airtight layer across the internal envelope on the warm side of insulation.

Continuity must be maintained at:

• Wall-to-floor junctions
• Wall-to-roof junctions
• Window and door reveals
• Service penetrations
• Structural interfaces
• Changes in substrate material

Substrate Preparation

Substrates shall be:

• Clean
• Dry
• Structurally sound
• Free from dust, laitance, grease and loose material
• Closed and consolidated prior to application

Gaps greater than 5 mm shall be filled using suitable cementitious filler or polyurethane foam.

Minor joints and surface irregularities to be sealed using compatible brush-grade membrane.

Excess foam shall be trimmed flush prior to coating.

Where the membrane is to remain exposed, substrates shall be pre-treated with Primer IM .

Environmental Conditions

• Minimum application temperature: +5°C and rising
• Do not apply during rainfall, frost, or where condensation is present
• Protect freshly applied membrane from moisture until fully cured

Penetrations and Junctions

All service penetrations shall be sealed to ensure airtight continuity.

Polyurethane foam to be installed around penetrations, trimmed flush once cured, and overcoated to form a continuous seal.

Particular care shall be taken at interfaces between dissimilar materials to accommodate differential movement.

Coverage and Continuity

Apply sufficient material to achieve full, uniform coverage and continuous membrane formation.

Ensure no voids, pinholes or weak points remain.

The completed system shall provide a continuous airtight, vapour control and gas barrier layer in preparation for air testing.