Thermofloc VSD Membrane - Vapour‑Retarding, Airtight Layer for Timber & Lightweight Construction - 1.5m x 16.7m roll

Thermofloc VSD (Variable Surface Diffusion) Membrane is a vapour‑retarding, airtight building membrane designed for use on the warm side of insulated building elements. It forms a continuous, controlled vapour‑resistance layer, preventing moisture from entering the insulation while still allowing limited diffusion to support safe drying of the structure. The VSD Membrane ensures reliable airtightness in roofs, walls and ceilings, helping to eliminate thermal bridges and uncontrolled air leakage. Its robust, tear‑resistant construction makes it suitable for both on‑site installation and factory‑prefabricated timber elements. The membrane is compatible with Thermofloc Adhesive Tape, Thermofloc Universal Adhesive Tape, and Thermofloc system adhesives, ensuring durable, long‑term airtight connections at overlaps, penetrations and junctions.

CHARACTERISTICS

• Airtight vapour‑retarding layer - protects insulation from internal moisture and air leakage.
• Optimised for cellulose insulation - ensures stable thermal performance and prevents settling risks.
• Controlled vapour diffusion - supports safe drying of the building envelope.
• High tear resistance - suitable for site installation and off‑site timber manufacturing.
• System‑compatible sealing - works with Thermofloc tapes and adhesives for durable joints.
• Suitable for roofs, walls and ceilings - universal use in timber and lightweight construction.

APPLICATIONS

• Internal vapour‑retarding layer in pitched roofs and flat roofs
• Airtight layer in timber‑frame walls
• Ceiling and intermediate floor constructions
• Factory‑prefabricated timber elements
• Renovation and retrofit projects