STRATEC® II S is a versatile synthetic roof underlayer, HPV type (High Permeability to water Vapour) with a high resistance to tearing. It can be laid, either in the traditional way, either on continuous substrate.


Due to its characteristics, STRATEC® II S can be laid directly onto the insulation and can also be used as rain barrier.

  • STRATEC® II S  has a double adhesive strip for the continuous junction of the longitudinal overlaps
  • STRATEC® II S holds the Roofing certification n° 11- 058


STRATEC® II S is laid in compliance with standards and DTU in force as well as installation rules for certified flexible roof underlayments (CSTB guidelines n° 3651- 2).

  • Traditional laying, stretched on rafters or roof trusses : STRATEC® II S is nailed with large head spikes or stapled on rafters.  
  • Direct laying onto insulation : the water vapour permeability (HPV) of STRATEC® II S allows to be laid directly onto insulation.
  • Laying onto continuous support (batten, CTBH particule boards, CTBX plywood panels...): the fastening is made with large head spikes (≥ 10 mm) through STRATEC® II  on the overlaps.


- Dimensions of the roll :

  • Length: ≥ 50 m
  • Width: 1,50 ± 0,02 m

- Weight of the roll: about 12 kg

- Colour: slip light grey topside / slip white underside avoiding slippage on rafters during installation

- Marking: each package bearing the CE marking

- Packaging: 20 rolls lying down per pallet

Regulations and approvals

  STRATEC® II S is used as indicated in the DTU 40.1 and 40.2 to protect roofs with discontinuous elements (60 cm maximal centres) against the penetration risks of powdery snow, dust, soot or pollen.

STRATEC® II S is appropriate as rainscreen for timber frame houses, in compliance with standards NF P 2- 204- 1 (DTU 31.2 – “timber frame houses and buildings”) and NF P 65- 210- 1 (DTU 41.2 – “Exterior wooden cladding”).