Marley’s top tips for installing extension roofs

Marley’s top tips for installing extension roofs

The high demand for extensions in the UK offers a great opportunity for builders this year and when it comes to roofing, there has never been so much choice. Here, Stuart Nicholson from Marley, gives his top tips for creating the perfect extension roof.

With lockdown restrictions forcing many families to stay at home for extended periods of time in 2020, extra space for living and working has become highly desirable. Together with low rates of borrowing and the relaxation in planning regulations, this is driving increasing demand for domestic extension, which is a great opportunity for builders and roofers this year.

Single storey rear extensions have become a particularly popular option for those seeking extra space. While homeowners often prefer the look of pitched roofs for this type of project, they do need to be carefully designed with both aesthetics and weatherproofing in mind. As well as trying to match to existing roof tiles, contractors will usually have to create a lower pitch roof, due to the position of first floor windows, which can make it harder to find a suitable roof covering.

The good news is that, over recent years, there has been a great deal of innovation in this area, with a wide range of easy-to-fix, cost effective, clay and concrete low pitch roof tiles on the market.

Here we give our top tips for choosing and installing the perfect extension roof:

  1. While the planning laws have been relaxed, you still need to match the new roof to the roofing material on the original property and in some designated areas, such as conservation areas, the homeowner will still need to get planning permission.


  1. Never be tempted to use a tile below the manufacturer’s recommended minimum pitch, even by half a degree, as it could invalidate your warranty! If you have to install at a lower pitch, then seek manufacturer advice as a weatherproof sub roof system may be required.


  1. If the tiles you want to use don’t go down to the minimum pitch you need, consult the manufacturer for alternative options. We have a wide selection of low pitch tiles that can be used to match a traditional clay, slate or concrete aesthetic. This includes the new Mendip 12.5, a concrete interlocking tile which has been designed for extension projects. Its special weatherproofing channels mean that it can be used down to a very low 12.5 degree pitch.


  1. If you need to match a traditional clay pantile roof, there are actually a surprising amount of low pitch options. Our easy-to-fix Lincoln interlocking pantile can now be used down to a minimum pitch of just 15 degrees and we also offer a traditional low pitch pantile, Eden, which is suitable for use down to 22.5 degrees.


  1. In low pitch projects, natural slate can be limited by geography because driving rain has to be considered. However, there are some very good slate effect tiles that can replicate the slate look at a lower pitch for extension work. For example, our Edgemere range of thin-leading edge concrete slates give a slate look but are more cost effective and can be used down to pitches of 17.5 degrees without geographical restrictions. They come in a variety of colours and textures, including Riven, to help contractors match the slate aesthetic they need.


  1. If you need to match traditional hand-made clay tiles for a double storey or side extension project, then clay handcrafted tiles are a great option as they are around half the price of a hand-made tile and give a similar rustic appearance. Our Ashdowne handcrafted clay tiles offer all the aesthetics associated with a unique handmade tile, but with all the benefits and cost effectiveness of a machine-made clay tile.


For more information about roof tiles for extension projects visit

How low do you need to go?

30 Degrees

Acme and Hawkins clay plain tiles

22.5 Degrees

Eden low pitch traditional clay heritage pantile

17.5 Degrees

Edgemere slate effect thin leading edge concrete tiles

15 Degrees

Lincoln Clay Pantiles

Wessex and Mendip interlocking concrete tiles

12.5 Degrees

Mendip 12.5 – Smooth Grey or Smooth Brown


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