Tyvek DuPont Dupont Airguard Reflective Membrane 1.5m x any metre length. Just enter number of metres required where it says 1 above.

Save on having 40 metres sat in the garage forever. Just buy what you need.

Application
DuPont AirGuard Reflective is a 100% air tight air & vapour control layer (AVCL) featuring a metallised surface with a very low emissivity internal vapour barrier that combined with an airgap can enhance thermal comfort by reflecting up to 95% of radiant heat back into the building.
AirGuard Reflective can be installed in roofs, below ceiling levels as well as in walls.

Effective condensation control

When installed continuously with all laps and penetrations sealed, DuPont AirGuard Reflective provides effective condensation control for all building types, including high humidity structures such as swimming pools or textile factories.

Installing airguard reflective

DuPont AirGuard Reflective can be installed either way round, but its reflective surface must always face an airspace. The preferred method is to install it with the reflective side facing into the building, then fix a standard 25mm batten over the membrane.