ISOLINE LOW LINE can be installed on purlins and ful deck on a roof pitch as low as 10 degrees for any roof tile. 

Designed to be used with all roof tiles, new or existing; ISOLINE® LOW LINE, lightweight bituminous sub-roof is fixed below the primary tile or slate roof covering, acting as the primary waterproofing layer of a roof, making roof tiles a secondary line of defence.

Watch the installation video or download the installation guide below.


ISOLINE LOW LINE Low pitched roofing solution



As light weight roofing systems and waterproofing specialists, Onduline's ISOLINE® sub-roof systems provide long-term protection against any potential water ingress that may happen over time through a breach in the primary roof covering, as well as being:

  • Ideal for retrofit or new roofing projects: existing tiles can be re-used.
  • Ventilaited: allows increased ventilation to minimise condensation and maintain excellent moisture control within the cavity, preventing mould build up.
  • Green credentials: the sub-roof is made up of 50% recycled cellulose fibres, contains no asbestos and does not release any hazardous substances.
  • Suitable for use with all major roof tiles.
  • Suitable for roof pitches as low as 10 degrees, which could mean an additional floor.
  • Tried and tested: BRE tested and BBA accredited.
  • Guaranteed with a 30-year waterproofing guarantee.