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Glidevale Protect Wunderlay®
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The product can be used for all pitched roof constructions (tiled and slated), whether the insulation is at ceiling joist level or at rafter level.


Protect Wunderlay is a heavy-duty type HR roofing underlay, designed for all cold and warm pitched roofs in conjunction with the provision of ventilation at eaves and ridge. The product can be used with a well-sealed ceiling and a separate air and vapour control layer on the warm side of the insulation or where the ceiling is not well-sealed as in a re-roofing application.

Features and benefits:

  • Completely water and airtight.
  • UV and heat resistant.
  • Good nail tear and tensile strength for its weight.
  • Does not generate nuisance noise under wind loading.
  • CE marked and BM TRADA certified.
  • Absorbent under surface prevents condensate drip off.
  • Embossed dark grey upper surface reduces glare and takes a chalk line marking.
  • Easy to cut and handle.
  • Achieves Zones 1-4 at 345 mm batten gauge (1367Pa), when tested to Annex A of BS 5534, ensuring wide coverage across the UK and throughout Ireland
  • Achieves Zones 1-5 at 310 mm batten gauge (2145 Pa).
  • Developed to overcome the disadvantages of traditional Type 1F and 5U felts and second generation plastic sheet materials.
  • Provides a secondary line of defence against wind-driven rain and snow and resistance to wind uplift.

General information









Supplied as a Roll


30000 mm

1500 mm widths only.

45000 mm

1000 mm widths only.


1000 mm

1500 mm


Pr_25_57_65_60 Plastics sheetsPrimary


H60/120 Concrete roof tiling

H60/105 Clay roof tiling

H61/105 Roof slating

H62/125 Roof slating

H62/105 Roof slating

H62/145 Roof slating

H64/110 Wood shingle/ shake roofing

H65/105 Clay roof tiling

H65/115 Concrete roof tiling

H65/135 Ceramic slate roof tiling

H65/125 Reconstituted slate roof tiling

H67/110 Metal roof tiling

H61/5 Roof slating

H60/3 Roof tiling

H62/3 Roof slating

H67/5 Metal roof tiling

H65/5 Roof tiling

H64/10 Wood shingle/ shake roofing

H65/10 Reconstituted slate roof tiling

Product range

Impermeable Underlays

Specification data - Plastics sheets




Roofing underlay (impermeable).


BS EN 13859-1, BS 5250, BS 5534, NHBC STANDARDS.

Performance characteristics


Tensile strength (minimum)

Manufacturer's standard.

Machine direction (along roll):

  • 233 N/50 mm: Unaged tensile strength to BS EN 12311-1 with mods.
  • 231 N/50 mm: Aged tensile strength to BS EN 12311-1 with mods.

Cross direction (across roll):

  • 246 N/50 mm: Unaged tensile strength to BS EN 12311-1 with mods.
  • 206 N/50 mm: Aged tensile strength to BS EN 12311-1 with mods.

Tear resistance

Manufacturer's standard.

  • 189 N: To BS EN 12310-1 with mods, along roll.
  • 199 N: To BS EN 12310-1 with mods, across roll..

UV stabilization

Manufacturer's standard.

UV and heat ageing conditions: UVA lamps at 50°C for 336 hours followed by heat ageing at 70°C for 90 days.

Third-party certification

BM TRADA Certified.


Non-woven, spunbonded

Twin ply construction comprising of a polypropylene non-woven layer, coated on one surface with a continuous film of polypropylene / polyethylene blend.

Physical properties



Dark Grey.

Embossed dark grey. Printed with product branding for ease of identification.

Weight (minimum)

120 g/m².

6 kg per roll.



Thickness (minimum)

0.49 mm.

Width (minimum)

45 m².

1000 mm.

Roll length (minimum)

45 m.


Installed below the primary roof covering onto rafters or sarking board.

Roof space ventilation should be provided at both low and high level as with all impermeable (type HR) roofing underlays irrespective of insulation type or position. Please see our ventilation products on NBS or contact us for further information.


Flexibility at low temperature


Class (minimum)

Resistance to water penetration to BS EN 1928


>2.0m hydrostatic head of water resistance

Wind resistance

Zones 1-4.

Wind uplift resistance (at 345 mm batten gauge) and 600 mm rafter centres - 1367 Pa.

Wind uplift resistance across the UK and Ireland - Zones 1-4 at 345 mm batten gauge to BS 5534.


Glidevale Protect FV250.

Glidevale Protect SV609.

Glidevale Protect In-line vents.

Glidevale Protect G range vents.

Environmental information

Contains Red List materials


Country of product manufacture

United Kingdom

Digital objects

Platform Compatible Version Certified to



Download now from NBS National BIM Library


Glidevale Protect Wunderlay®

Glidevale Protect Wunderlay®

Third party certifications

BM Trada

BM Trada

Protect Wunderlay BM TRADA Certificate No CPS-001

BM Trada

BM Trada

Protect Wunderlay BM TRADA Schedule No CPS-009

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