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Covertek 403 (roof)

Covertek 403 Plus is a fire retardant, absorbent and breathable synthetic roof underlay, constructed using a microporous water resistant film sandwiched between two layers of spun-bonded polyolefin. Designed as a means of managing condensation, water vapour transfer and water ingress in roof applications.

Key Features

  • BRANZ appraised
  • High water barrier
  • Fire retardant
  • Breathable
  • Absorbant
  • Strong & durable
  • Light weight


  • Can be used in direct fix or cavity fix for roof construction.
  • Is more stable and more shrink resistant than kraft paper based underlays.
  • May be installed during adverse conditions (rain/snow) without affecting its durability and performance.
  • Will not increase the risks of condensation as compared with comparable kraft paper underlays.
  • Has a 150mm lap line printed edge.