Undertile Membrane

Marley Roofing’s New Agrément Certified Undertile Membrane, offers an affordable roofing underlay that performs an important function in preventing excessive pressure build-up inside the roof during wind gusting. In addition, it provides a safeguard against possible rainwater penetration in extreme conditions and acts as a safeguard against dust penetration.
  • Agrément South Africa: 2014/469 Certification
  • Occupancy Classification - SANS 10400: Table 1 of regulation A20 (1)
  • Adheres to SANS 10177-10 fire rating
  • Reduce air leakage and ingress to the roof space of wind    


2 Layers laminate made up of 38 gsm LDPE Bonding and 80 gsm Spunbond


Dimensions: 1.5m x 30m

Coverage: 45m2 (nom.area excluding overlap)

Coverage: 40,5m2 (nom.area including overlap)

Mass per Unit Area: 118gm2


Marley Undertile Membrane should be stored in a clean, dry environment and should not be exposed to direct sunlight.


  1. The membrane is installed horizontally across the rafters, starting at the eaves, with each subsequent layer overlapping the lower layer by 150mm (minimum), with the overlapping line of 150mm facing   upwards.
  2.  The membrane is tacked to the trusses with sufficient galvanised clout nails to secure the membrane in position until the battens are installed on top of the Marley Undertile Membrane.
  3. The membrane between the trusses must be sufficiently taut, while allowing a shallow trough to facilitate run-off should rain water penetrate the tiles.
  4.  At the eaves it is important that the membrane is taken from under the second-last tiling batten over the tilting batten to prevent ponding of water.
  5. Tilting battens should be installed as soon as possible to prevent damage to the membrane by wind, and roof tiles placed to minimise exposure to the sun.