We answer your questions about low pitched roofing!

Are you planning a single storey home extension which requires low pitched roofing? Heard your architect, builder and/or roofing contractor talk about low pitched roofing and want to know more? We’re here to help. We’ve answered all of the commonly asked questions in regards to low pitched roofing below…

ISOLINE roofing

This barn in Chelmsford is undergoing a single-storey extension with the help of our ISOLINE LOW LINE system! Find out more about this product below...

What is classed as a low pitched roof?

In the UK, a traditional roof pitch is generally between 30 and 50 degrees, a low pitched roof is usually classed as anything between 10 and 30 degrees.

ISOLINE low pitch roof

Why choose a low pitched roof?

A low pitched roof is the preferable alternative to a flat roof as it allows for better drainage and protection against the elements. It is also a great option for homeowners looking to extend their property without the need for planning permission, as there has been a permanent relaxation of planning rules and homeowners can now add a single storey extension to their home without the rigmarole of obtaining planning permission.

However, note that if you live in a conservation area you will need to check with your local authorities as to whether permission still needs to be obtained.

What are the key factors to think about when planning a low pitched roof single storey extension?

  • Match your existing roof tiles - a sticky situation if the material in question is no longer available and, in this case, you might need to replace your existing roof and cover the new extension with new roofing tiles, adding an unexpected cost to your project if not properly planned
  • Check the minimum pitch of your chosen tiles - another area where you can get caught out and face an unexpected cost so always follow the manufacturer’s recommended pitch for your roofing tiles. Even the smallest difference - one degree will do it - will not only negate your guarantee, but it may also result in a leaking roofing system, causing you more costly problems when the winter weather seeps through the layers underneath and into your home extension itself
  • Water run-off - it is highly likely the low pitched roof on your single story extension will need to cope well with water running off from a higher, larger roof. If the system is not competent enough to make sure the water is able to sufficiently run off the roof, you will end up with costly leaks
  • Effective drainage - this goes hand in hand with water run-off. The water needs to drain away from your property and the drainage system surrounding your low pitched roof needs to be able to deal with not only the water running of the low pitched roof but the water running off of the larger, higher roof above

What is the best underlay for low pitched roofing?

We may be a tad biassed but let us tell you why our ISOLINE LOW LINE roofing system is the best underlay for low pitched roofing.


Acting as a waterproof barrier underneath your roofing tiles, it allows your roof tiles of choice to be the secondary line of defence, enabling the pitch of the roof to be much lower. With this, there are many benefits it can bring…

  • The low height corrugations of just 24mm make it ideal for low pitched roofs as low as 10 degrees!
  • The 21 corrugations per sheet give it maximum rigidity but it is also super lightweight and easy to handle and manipulate
  • It has been engineered to be 100% leak free
  • It is simple and stress-free to install It can be and is commonly used on heritage sites It can be used under any type of roofing tile as a secure waterproofing layer
  • BRE tested and BBA accredited it has been proven to be at least three times less likely to leak compared to a traditional tile system
  • Eco friendly, it is made up of a minimum of 50% recycled cellulose fibres
  • It contains no asbestos It does not release any hazardous substances
  • It comes with a 30-year warranty when installed correctly
  • The ISOLINE LOW LINE accessories including; batten cloaking piece, eaves ventilator, eaves tray, and abutment flashing help to increase the watertightness and weatherproofing of your roof even further

With our ISOLINE LOW LINE roofing system you'll have everything you need to create an effective, weatherproof low pitched roof!

Ready to get started?

Ready to get started on your home extension? Speak to your builder, architect, roofing contractor or other professional about our ISOLINE LOW LINE roofing system. Or get in touch with us directly by calling 0207 727 0533 or emailing [email protected]. We will be more than happy to discuss your project with you and how our roofing system can help you achieve your desired performance.