Home Breather Membrane Fire proof membrane PERMAFOL


Insulating & permable roof underlay

 fireproof membrane



Breathable membrane and insulation



Excellent fireproof properties



all other breathable foils available


Only requires




on breather, battens, fixings and labour

Key features

High performance and versatile construction membrane.

Excellent thermal, waterproof, soundproof and airtght properties.

Fireproof - prevents the spread of fire in all buildings.

Ideal solution for timber frame wall insullations and house wraps, as well as roofs.

Perfected for thatched and listed buildings.

Same thermal behaviour as 240mm of mineral wool.

Breathable - releases moisture and prevents batten rot.

Its thermal mass greatly reduces the risk of 'thermal bridge'.

Permafol super thin insulating breather membrane provides a far greater thermal efficiency, easy of insulation and protection against condensation compared to all other leading products.

Permafol is an extremely high performance and versatile construction membrane with many unique properties that offer an ‘all in one’ solution for construction. Permafol is ideal as a roofing membrane because it offers a waterproof and breathable layer with excellent thermal, soundproof and airtight properties as well as being completely fireproof.

The unique properties of Permafol make it perfect for thatched and listed buildings by offering complete fire protection, a substantial level of insulation, increased soundproofing and a high level of breathability that will maintain the integrity of the building.

Watch our video now to see Permafol in action

Click to download in MP4 format (34.32MB)

U-value with Permafol applications

Thermal performance EN 16 012

Core R-value 0.47 m2K/W
R-value with 2 air gaps 1.7 m2K/W
Emissivity 5%

 Permafol (2 air gaps) with 100mm PIR or 145mm Glass Wool

U-value = 0.16 W/m2K

Minimum thickness of additional insulation with PERMAFOL (with 2 air gaps):

  Target U-value (W/m2K)
0.25 0.20 0.18 0.16 0.15
PIR (0.022 W/mK)
50mm 75mm 90mm 100mm 110mm
Glass wool (0.032 W/m)
permafol-glass wool 0.032
75mm 110mm 125mm 145mm 160mm
Glass wool (0.035 W/mK)
permafol-glass wool 0.035
80mm 120mm 140mm 160mm 180mm



  fully tested to BS EN 13050
Weight, g/m2   1200 g/m2
Thickness, mm   10
Roll weight, kg   24
Roll diameter, mm   420
Fire rating Euroclass A2-s1,d0 BS EN 13501 non combustible
Water vapour permeability Sd, m BS EN 13859 0.05
Nail tear resistance R3, kg BS EN 13859 28.4
Waterproofing, class BS EN 13859 w1
Sound reduction Rw, dB BS EN 717-1 41 in situ
Emissitivy BS EN 16012:2012 0.05
Reflectivity, % BS EN 16012:2012 95
Core resistance  BS EN 16012:2012 R 0.47
Thermal conductivity BS EN 16012:2012 0.0278
Overall resistance in situ BS EN 16012:2012 R 1.7
Roll size: 1m x 18m   18m2




Following the success of the Queen’s award winning Easy Verge, here at Permavent we are proud to announce the launch of the recently developed Easy VergeTrim. This latest addition to the Easy Roof System has been specially designed to meet the requirements of the Scottish and refurbishment markets.