SBS-modified bitumen polyester reinforced ultralight underlay membrane for pitched roofs with mechanical fixation

SBS-modified bitumen membrane UNDERLAY PRO (S) 500 is used as an underlayment for roofing shingles in systems of pitched roofs with mechanical fixation (nailing). The material is installed on the continuous rigid wood decking (OSB-3, plywood, tongue or groove planks). Cannot be used in zones of valleys and eaves as these areas are most prone to leakages and require the application of self-adhesive membrane UNDERLAY NEXT SELF or ULRAFLEX SA.

Waterproofing material UNDERLAY PRO (S) 500 has the following advantages:

  • Additional strength granted by polyester reinforcement;
  • Excellent physical and mechanical characteristics ensure extra durability;
  • The bottom side of the material is covered with fine-grained sand, the top one – with spunbond that prevents applicators from slipping from the pitched roof;
  • Ultralight weight of the membrane makes application on the roof slope easier and safer;
  • The high-quality polymer-bitumen compound has the property of self-healing, which grants absolute tightness in places of nail penetration;
  • Also available in a variation with longitudinal thermoactive bitumen overlap strips for increased convenience and speed of application – UNDERLAY PRO (S) 500 stick.

Product technical data

Mass per unit area, kg/m2 0.5±0.1
Length x width, m 25 x 1
Flexibility at low temperature, °C ≤-20
Flow resistance at elevated temperature, °C ≥120
Elongation L / T, % 40±10 / 40±10
Tensile strength L / T, N/50 mm 500±150 / 400±100
Tear resistance L / T, N 180±50 / 180±50
Reinforcement type polyester
Protective covering type on the top spunbond
Protective covering type on the bottom fine-grained sand