ISOLINE LOW LINE Sub-Roof
Waterproofing for all roof tiles. And that's guaranteed!
FIT ANY ROOF TILE WITH ISOLINE.
Any tile, old or new, and still keep your roof watertight, even at a pitch as low as 10 degrees.
ISOLINE LOW LINE is our easy to install bituminous sub-roof system for installation beneath any roof tile at a pitch as low as 10 degrees.
ISOLINE LOW LINE. The long-lasting, waterproofing solution for heritage, retrofit and new builds that will ensure protection against even the harshest weather. And that's guaranteed.
What is ISOLINE LOW LINE?
ISOLINE LOW LINE. The sustainable option for a long-lasting, waterproofing solution that will ensure protection against even the harshest weather.
Designed to be used with all roof tiles, new or existing; and specifically for use on low pitch roofs, this lightweight bituminous sub-roof system is used as a secured waterproofing layer, under the tiled roof. This solution is a perfect waterproofing barrier against potential leaks, that may happen over time through a breach in the tiles covering.
What is a sub-roof?
A sub-roof is an additional protective layer within the roof structure, acting as the primary waterproofing layer under the tiles when the tiles' minimum pitch cannot be met. British Standard BS 5534 acknowledges situations where using roofing products below the recommended pitch is challenging and emphasises the need for a functional weatherproof sub-roof system.
Sub-roof systems change the dynamics of traditional roof structures. Instead of relying solely on tiles for waterproofing, the sub-roof becomes the main waterproofing layer, allowing the tiles to serve as a secondary defence against water ingress.
Increased ventilation
With a corrugation height of just 24mm, ISOLINE® LOW LINE is fixed below the primary tile or slate roof covering, thus, making roof tiles a secondary line of defence enabling the pitch of the roof to be much lower than the minimum as recommended by the tile manufacturer.
Due to the corrugations, ISOLINE® LOW LINE allows increased ventilation and airflow both above and below the sheet and tile battens positioned above the corrugations allow moisture to drain to the eaves which, with the enhanced ventilation, maintains excellent moisture control within the cavity.
Why use ISOLINE LOW LINE?
The ISOLINE® LOW LINE sub-roof system is:
- Ideal for retrofit or new roofing projects: existing tiles can be re-used.
- Ventilaited: allows increased ventilation to minimise condensation and maintain excellent moisture control within the cavity, preventing mould build up.
- Green credentials: the sub-roof is made up of 47% recycled cellulose fibres, contains no asbestos and does not release any hazardous substances.
- Suitable for use with all major roof tiles.
- Suitable for roof pitches as low as 10 degrees, which could mean an additional floor.
- Tried and tested: BRE tested and BBA accredited.
- Guaranteed with a 30-year waterproofing guarantee
- All types of concrete, slate, and clay roof tiles can be installed at pitches as low as 10°.
When to use ISOLINE LOW LINE:
Several factors influence the selection of a roof pitch, including material availability and cost, aesthetics, construction ease or difficulty, weather conditions, and local building permissions.
Roof pitches not only contribute to a building's aesthetic appeal but also play a crucial role in its functionality and durability.
Click here to view completed case studies using ISOLINE LOW LINE
Low Pitch Solution
ISOLINE LOW LINE is the only sub-roof system in the UK to be BRE tested and BBA accredited to as low as 10o with a 30-year guarantee. Made from approximately 50% recycled material and specifically designed for use on low pitch roofs, this lightweight bituminous underlay sheeting is fitted under roof tiles, thus being shielded from elements such as wind and rain, making it an exceptional long-lasting waterproofing solution.
Just like our duck suggests, it's probably more waterproof than him...
Heritage Sites
One significant advantage of the ISOLINE LOW LINE sub-roof system is its ability to accommodate heritage sites and older properties. By allowing the use of existing or reclaimed tiles, the sub-roof maintains the original look and feel of the property while providing an additional layer of protection against water ingress.
Home Extensions
The choice of roof pitch becomes crucial in home extensions, with flat roofs being a common option due to their space-saving and contemporary aesthetics. However, pitched roofs, especially those matching the main property, contribute to a more cohesive visual appeal. The introduction of low-pitched roofs in extensions provides an opportunity to use matching tiles, ensuring uniformity with the existing property.
Get In Touch
Do you often come across situations where the chosen tile for your project restricts your design and overall aesthetic due to pitch limitations?
ISOLINE LOW LINE is the solution.
- Any tile can be used on your project as low as 10 degrees
- Easy and fast installation
- Eco-responsible
- Cost-effective
- Guaranteed waterproofing
Get in touch today. Our team of experts are available to assist you, email: [email protected] or call 0207 727 0533.
RIBA CPD
Our RIBA accredited CPD is available to give architects and building professionals a greater understanding of the benefits low pitched roofs and sub-roof systems can offer.
‘Understanding low pitched roofs and the benefits of sub-roof systems’ is the latest addition to Onduline’s extensive training programme and provides an overview of the importance of roof pitches and how to ensure the right pitch for a building.
