Permavent Non-Breather 120

Permavent Non-Breather 120


Permavent Non-Breather 120 roofing underlay has been developed using next generation technically advanced methods to produce a class leading High resistance underlay. Permavent Non-Breather 120 is a fourth generation roofing underlay that can be used in unsupported and supported pitched roofing applications slated or tiled. The dual structure nonwoven and PP provides HR120 with superior tensile and nail tear strength delivering unrestricted use from zones 1 to 5 at 345mm batten gauge to BS5534. Ventilation should be provided below the underlay (type HR) in accordance with BS5250 – Management and Moisture in Buildings. .


  • Can be laid directly over sarking
  • UV and heat safe
  • Exceeds BS 5534 wind loading requirements zones 1 to 5 – unrestricted use
  • Entirely air and watertight
  • Ease of installation
  • Available in 1m x 45m roll
  • UKCA marked


Weight, gsm120
Resistance to water penetrationw1
Aged tensile strength (MD), N/50mm>150
Aged tensile strength (CD), N/50mm>100
Elongation at max. tensile force (MD), %NPD
Elongation at max. tensile force (CD), %NPD
Resistance to tearing, (along) N>70
Resistance to tearing, (across) N>70
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