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Protect Wunderlay Impermeable Underlay


£40.73 Incl. VAT
£33.94 Ex. VAT

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Estimated Delivery: 2-3 working days 


The Protect Wunderlay is a high-resistance, impermeable underlay. An ideal solution for cold or warm pitched roofs where traditional ventilation is being used, the non-breathable membrane provides a perfect alternative to 1F felt, 5U felts and second-generation plastic sheet materials. Offering impressive wind uplift resistance, the Wunderlay impermeable underlay can be used in wind zones 1-4 without the need for additional sealing tapes.

The Wunderlay is completely water and airtight. Its high-quality polypropylene composition is strong and durable, as well as UV and heat resistant, giving you long-lasting peace of mind both during and after construction*. Lightweight at 120 grams per meter squared, the mid-level membrane is easy to cut and handle, and effortless to install. Roofing Supplies UK are pleased to offer the Protect Wunderlay impermeable underlay in two sizes, simply select the option that suits your needs from the dropdown box.  

Why Choose this Protect Wunderlay Impermeable Underlay?

  • Suitable for cold & warm ventilated pitched roofs
  • Water & airtight
  • UV and heat resistant
  • Strong & durable
  • Lightweight alternative to felts and plastic sheeting
  • UKCA/CE certified

Product Specifications:

Size: 1m x 45m / 1.5m x 30m (select from dropdown)

Colour: Dark grey

Weight: 120 g/m²

Material: Polypropylene with polyethylene/polypropylene blend film coating

Resistance to Water Penetration: W1

Unaged Tensile Strength (MD / CD): 233 / 246 N/50mm

Aged Tensile Strength (MD / CD): 231 / 206 N/50mm

Nail Tear Strength (MD / CD): 189 / 199 N

UV Stability: 3 months

Wind Zones: 1-4 at 345mm batten gauge (resistance to wind pressure 1367 Pa), when tested to Annex A of BS 5534

Please note: *An impermeable underlay is not a total waterproof barrier and if used as a temporary waterproof covering, some rain penetration may occur. In certain conditions, particularly if there is persistent heavy rainfall combined with subsequent freeze/thaw conditions, an underlay should not be exposed for more than a few days. In the event of severe weather conditions, the product should be covered with tarpaulin (referenced in BBA Bulletin No 2. “Guide to Good Site Practice”)

Deliveries are made on the basis the customer can accept the goods, or willingness to off load the goods, or having means of mechanical offload, this also applies to heavier items such as pallets etc. All deliveries are made ‘kerbside’ and often it can be at the discretion of the driver. A large majority of deliveries would be made on a large rigid tail-lift vehicle and off loaded via a pallet truck and only on to flat surfaces such as tarmac, concrete and pavers. If you do have restricted access, please contact us prior to placing your order. We will always try to accommodate your needs. If a delivery fails due to access, we reserve the right to make a re-delivery charge. All delivery charges are calculated when checking out. The delivery charges included are for the Mainland UK only and do not apply to the Scottish Highlands, or Isles off the Mainland. Additional charges may apply for deliveries that aren’t classed within the Mainland (this is classed by ourselves, suppliers and couriers) Please contact us on 01752 466151 or Due to the nature of our business model, this can mean your order will be sent via multiple deliveries. Whilst we will make every effort to deliver your goods within the stated/requested time frame, we cannot guarantee availability from the manufacturer or the manufacturer's delivery schedules, so we would recommend the end user not to start/schedule any work until the goods arrive. Due to logistics of various couriers and suppliers we are unable to give times of deliveries. However, please call or email us on the day of the delivery and we will try to get an approximate time. Deliveries can take place from as earlier as 07:30 right up to 18:00 depending on the courier/haulier and taking into account local traffic etc.
You have 14 days from receiving your item(s) to return them should you wish to do so. Please contact us should you wish to arrange a refund/return. Any product marked cut to size, bespoke or made to order are non returnable and excluded from our refund policy.

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