Proctor Air® - Air & Vapour Permeable Membrane

Proctor Air® is an air and vapour permeable, water resistant roofing underlay. Its characteristics allow even very complex pitched roofs to breathe, without the need for air gaps or secondary venting.

The meltblown core at the heart of Proctor Air allows natural air movement to ‘supercharge’ the passage of moisture vapour from the roofspace, making the formation of condensation in the roofspace virtually impossible.

A unique feature of Proctor Air’s BBA certificate is the clarification that it can be used on roofs featuring solar PV.

Product Features

Vapour permeable
Fully air permeable
Water resistant
Wind Uplift Resistance Complies with BS5534
More uniform airflow than vents
No VCL required
15 year warranty
BBA Certificate no. 24/7147
Compatible with PV Assemblies
EPD Certified

Key Features of Proctor Air

Vapour Permeable

Proctor Air has an Sd-value of 0.015m and a vapour resistance of 0.075 MNs/g, making Proctor Air one of the highest performing vapour-permeable membranes on the market. (Vapour permeable underlays are sometimes referred as “breather membranes”)

Fully Air Permeable

Air permeable membranes allow air movement through the roof, as well as allowing moisture to escape by diffusion. This means that condensation is far less likely to form on the membrane itself, and also allows the membrane to deal with much higher moisture levels within the building, for example during the drying out period.

Water Resistant

The membrane can be left exposed for up to three months to UV exposure, however for water resistance we recommend the exposure time is reduced to as short a time as possible. If leaving exposed we would advise a temporary cover such as a tarp, especially in inclement weather and in refurbishment projects.

More Uniform Airflow than Vents

The air permeability of Proctor Air means a non-ventilated roof fitted with Proctor Air allows a more consistent air flow through the roof than a roof ventilated as per BS5250, without expensive and time consuming ventilation hardware fitted to the roof.

No VCL Required

Installing Proctor Air will mean that a vapour control layer is not required for non-ventilated cold pitched roof constructions.

15 Year Warranty

Proctor Air’s 15-year warranty provides peace of mind