Powerlon UltraBlock 300 is a high-performance Air and vapour control layer (AVCL) designed to enhance insulation efficiency and reduce energy loss in both commercial and residential buildings. This 270gsm membrane features a thermo-reflective surface that works by reflecting heat back into the building, significantly improving energy efficiency while helping to manage interstitial condensation. Manufactured using reinforced polyethylene and encapsulated aluminium foil, this vapour control membrane acts as an impermeable air barrier, offering exceptional vapour resistance and airtightness. The Powerlon UltraBlock 300 thermo-reflective VCL is especially effective in roof and wall applications, where controlling the movement of water vapour is critical. Its metallised barrier layers and reinforced polyethylene membrane construction make it a robust and long-lasting solution, providing superior performance when compared to standard vapour barriers. Ideal for projects requiring a reflective vapour control layer, this 2m x 50m roll is easy to handle and install. Product Highlights: Thermo-reflective layer reflects radiant heat back into the structure Creates an impermeable air barrier High vapour resistance to prevent interstitial condensation Durable reinforced polyethylene with metallised barrier layers Improves insulation performance and overall energy efficiency Ideal for roofs, ceilings, and walls Installation Guidelines andndash; Powerlonandreg; UltraBlock Continuity: Ensure Powerlonandreg; UltraBlock membranes are installed continuously across the entire structure. Minimise joints wherever possible. Sealing Joints: All laps and joints must be sealed using Powerbondandreg; FR Aluminium Tape. For superior performance, apply a continuous double row of Powerbondandreg; Butyl Tape, spaced 75?mm apart, before sealing with the aluminium tape. Cold Roofs: When used in cold roof applications with the membrane draped between purlins and insulation above, sealing laps can be more difficult. In high-risk areas, install a rigid lining sheet throughout to support the membrane. Warm Roofs: In warm roofs where the membrane is supported directly by the structural deck, sealing is easier. The sealing tapes accommodate slight expansion or contraction in the deck. Penetrations andamp; Airtightness: Keep service penetrations (e.g. soil pipes, vents, rooflights) to a minimum. Ensure airtight seals at every point of entry and along the roof perimeter. Laying the Membrane: Lay Powerlonandreg; UltraBlock loosely, flat, and free from folds or wrinkles. Avoid creases that can compromise performance. Temperature andamp; Weather Conditions: Do not install at temperatures below 5 degree celcius, as the membrane becomes less flexible. Avoid installation in windy conditions, which can make handling difficult. Fixings andamp; Support: Timber frame fixings must not puncture the membrane. Only make joins where the membrane is fully supported. Joining Technique: Press all sealed overlaps firmly using a hand-held pressure roller. Tapes should only be applied in temperatures above 5 degree celcius. Inspection andamp; Repairs: Before covering, inspect the membrane thoroughly to ensure all seals are intact. Any damage must be repaired using a patch of Powerlonandreg; UltraBlock, fixed with a double row of Powerbondandreg; Butyl Tape, 75?mm apart. Patches should not extend more than 150?mm beyond the damaged area. UV Protection: The membrane must be protected from UV exposure. Complete construction and cover the VCL within 3 months of installation. Overlap Requirements Horizontal overlaps: Minimum 150 mm Vertical overlaps: Minimum 150 mm Please refer to the full installation manual for detailed instructions and best practices.