However, like many roof tile manufacturers, Northstone faced a common challenge - offering viable solutions for low-pitched roofs. Traditionally, these projects are outside the scope of many roof tile products due to tile minimum pitch limitations and the consequential increased risk of water ingress at low pitches.

Due to housing shortages many people are opting to extend or renovate their existing property to suit their family and lifestyle needs. Planning regulations have also become more flexible, particularly around commercial property, extensions and renovations therefore the demand for low-pitch roofing solutions has increased. Property owners, both residential and commercial, are drawn to the clean, modern aesthetic of low-pitch roofs but often still want the familiar look of traditional roof tiles. This growing trend has created a real need for roofing solutions that combine strong performance with visual consistency, while also delivering reliable waterproof protection.

Recognising this need, Northstone sought to provide a solution that met demand without sacrificing the performance of their roofing products. This led to a strategic partnership with Onduline Building Products and the adoption of the ISOLINE® LOW LINE system, an advanced sub-roof solution designed to address the challenges of low-pitched roofs in both commercial and residential applications.

Unlike flat, non-breathable systems, the corrugated structure of ISOLINE® LOW LINE enhances ventilation, preventing moisture build-up and timber rot, making it a durable and reliable option for roofing professionals. This system gives contractors the confidence to tackle low-pitch projects that might otherwise have been turned away.

Currently, the only BRE-tested and BBA-accredited sub-roof system in the UK that can be used on pitches as low as 10°, ISOLINE® LOW LINE comes with a 30-year guarantee. This accreditation assures roofing professionals of the system’s performance and reliability, enabling them to confidently take on low-pitch projects that were once off-limits.

Northstone’s recent partnership with supermarket chain Aldi demonstrates how ISOLINE® LOW LINE can overcome complex roofing challenges in commercial settings. Several Aldi stores were affected by ongoing roof issues, made more difficult by low-pitch roof designs and long rafter lengths. Northstone needed a solution that could ensure reliable waterproofing while accommodating tile use across a large area. By specifying ISOLINE® LOW LINE, they were able to deliver a robust and aesthetically pleasing result, covering approximately several metres of roof across all stores.

As low-pitched roofs continue to grow in popularity across both commercial and residential sectors, the partnership between Onduline and Northstone illustrates how innovation, sustainability, and collaboration are reshaping the roofing industry. By offering practical solutions to previously challenging roof designs, this partnership is opening new commercial possibilities while also evolving the solutions available for domestic applications.