Home > Companies > Garland UK > StressPly® Evolution

An elastomeric modified bitumen waterproofing membrane manufactured in a superior calendaring process by saturating and coating a polyester carrier with a waterproofing compound made from a special grade of modified bitumen, with SBS elastomers and fillers. The SBS modifiers boost the thermal, mechanical and aging characteristics of the membrane compound; the non-woven spun-bond polyester carrier reinforcement provides the membrane with its excellent tensile strength, tear/ puncture resistance and elongation properties. StressPly Evolution upper surface is finished with mineral slate, while the lower face is laminated with thermo-fusible polyethylene film.


  • High UV resistance – StressPly Evolution with its mineral slate upper finish offers excellent protection from the damaging effects of UV radiation.
  • Excellent chemical and bacteria resistance – the special grade of modified bitumen used in the manufacture of StressPly Evolution has excellent resistance to alkaline solutions, light acidic solutions and bacteria.
  • Superior strength – the StressPly Evolution membrane is reinforced with high strength polyester. The superior strength provided by the polyester scrim resists the movement created by today’s modern buildings. In addition, the polyester scrim in StressPly Evolution provides tensile strength in excess of 1000 N longitudinally. This translates to long-term resistance to splits and tears in the completed StressPly Evolution roof system.
  • Absolute impermeability to water – the exceptional formulation of StressPly Evolution means that the membrane is impermeable to water, coupled with excellent thermal, mechanical and ageing characteristics.


Can be used in conjunction with other Garland High Performance Roofing products, as well as with conventional polyester felt underlayment. Specifications for torch applied roofing systems are available. It can also be used to repair splits, cracks or other deteriorated areas of an existing asphalt based roofing system.

Standard product features


Non-woven polyester, reinforced with fibre glass filaments (composite).

Compound type:

Bitumen modified with elastomeric rubber (SBS).

Surface finish:

  • Upper side: Mineral slate.
  • Lower side: Polyethylene film.

Size (l x w):

6 x 1 m.


4 mm.

Technical properties:

  • Breaking elongation (L/ T): 46/ 47%.
  • Dimensional stability: ±0.2%.
  • Low temperature flexibility: -14°C.
  • Resistance to tearing (L/ T): 200/ 300 N.
  • Tensile strength (L/ T): 1040/ 480 N/50 mm.
  • Watertightness: 60 kPa.

Reaction to fire (to EN 13501-1):

Euroclass E.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-65-50/301 Reinforced bitumen sheets for roofing

NBS Specification

NBS Buliding logo
This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Garland UK


+44 (0)1174 401050

Product reference

StressPly® Evolution

Manufacturer details

The Garland Company UK Ltd,
Second Way,
Bristol, BS11 8DF
Tel +44 (0)1174 401050
Fax +44 (0)1174 401057
NBS Plus