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WonderBuilds 180 Sanded Underlay 20m x 1m


£65.99 Incl. VAT
£54.99 Ex. VAT

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Estimated Delivery: 2-3 working days. Please note - if you live in Scotland, we will need to quote you for delivery.


The WonderBuilds 180 Sanded Underlay is a high-performance waterproofing solution designed for use in built-up roofing systems. Saturated and coated with SBS modified bitumen, the underlay is finished with fine grain sand on both sides and is reinforced using high-quality polyester.

Strong and durable, this membrane meets the requirements for new builds and refurbishments alike. The versatile WonderBuilds 180 Sanded Underlay is compatible with most Pour and Roll and Torch On materials.

Why Choose this WonderBuilds 180 Sanded Underlay 20m x 1m?

  • High-performance waterproofing solution
  • Polyester reinforced
  • Sand coating on both sides
  • Quick & easy to install
  • Strong & durable

Product Specifications:

Material: SBS modified bitumen

Base Carrier: 180g spunbond polyester

Upper Face Finish: Fine mineral granules

Lower Face Finish: Silica sand

Roll Dimensions: 20m x 1m

Weight (kg/m²): 1.8

Visible Defects: Pass

Watertightness: Pass

Straightness: Pass

Tensile Strength (N/50mm): 890 (LD) / 590 (TD)

Elongation at Maximum Load (%): 38 (LD) / 46 (TD)

Resistance to Tearing (N): 150 (LD) / 140 (TD)

External Fire Performance: TROOF (t4)

Fire Reaction: Class F

Cold Flexibility (°C): ≤ -5

Flow Resistance at Elevated Temp (°C): -0.3

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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