Duo Classic & Longlife Extra

DUO is a great roof underlay from the base quality assortment. Quick, easy to maintain and resistant - the best DUO protection description. DUO is an extremely durable three layer underlay, both impermeable and resistant membrane. This roof underlay is used for sloping roofs as a "breathable" roof film, but can also be used as a rain protection for the facade.

Benefits and features

  • The water vapor permeability coefficient is very low (Sd is 0.02 m), which guarantees that the roof will be dry and ventilate. The roof will be able to "breathe".
  • Suitable for pitched roofs, can also be used as rain protection in enclosed facades (without open joints).
  • Its tensile strength and rupture resistance are exceptional. There is no risk of climbing the clutches.
  • DUO is laid directly on thermal insulation or on a wooden base (strip). The ventilation gap between the roofing film DUO and the insulation is not necessary, so all rack heights can be used to apply thermal insulation.
  • Longlife Extra option, with two existing adhesive tapes, facilitates the work of the coating and contributes to thermal insulation of the building: the insulation of the roof diffuser underlay is excellent for wind.

The DUO's roofing diffuser underlay has a 10 year warranty.



Technical data Standard Duo
Material 3 layers: 2 polypropylene layers on the outside, 1 microporous film
Tensile strength EN 12311-1
EN 13859-2
MD: 310 N/5 cm
MCD: 240 N/5 cm
Friction resistance with nails EN 12310-1
EN 13859-2
MD: 180 N
MCD: 210 N
Sd value EN ISO 12572 0,02 m
Working temperature -40°C to +80°C
Weight EN 1849-2 ca. 150 g/m²
Color Light grey
UV resistance No more than 4 weeks as a temporar roof cover
Fire rsistance EN 13501-1 E
Water resistance EN 1928 W1

Roll specifications

Characteristic Standard Duo
Roll length EN 1848-2 50 m
Roll width EN 1848-2 1,5 m
Roll weight approx. 11 kg
Roll amount on a pallet 24


  • Nailing: Automatic or manually screwed flat head. The nail can be forged before it is not perforated. The vinyl head can not penetrate into the diffusion roof underlay. The vinegar must be adjusted to a coarse force.
  • Stapelling: Automatic stapelling. The staple can not be pressed too deep in the roof underlay. The hatchet must be tuned to a consistent force.


  • Rolls should be placed on a clean, dry surface.
  • They must be stored in an indoor temperature range of -10 to + 80 ° C.
  • When storing DUO rolls must be protected from rodents, insects and sun.

Full installation advices you can download here.

Download underlays installation guide

Technical documents

Technical documentation with information and specifications can be found in the Downloads section.

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