If you are a looking to replace your roof and you are aiming for a flat roof, you are certainly worried about how much it is going to cost you. Fortunately, we share your concerns and this is why we have created this detailed cost guide.

flat-roof-pricesFlat roofs date back to 2000 BC, during the Minoan period. In those days they were constructed of timber or thatching to block out bad weather, but now things are a little more advanced than that! Before you decide on installing a flat roof, it is worth considering the cost vs. maintenance factor – whilst flat roofs generally cost less to install, they often cost more in maintenance costs over the years.

Flat Roof Prices – Estimated Cost

Even though this article is well researched and tries to provide as much as possible accurate estimations, flat roof pricing will always vary depending on the local roofer that you have contacted. Please try to read carefully this article and use it mostly as a guide.

What are the benefits of a flat roof?

  • Flat roofs can keep your home considerably warmer than their competitors, especially during the cold winter months. This is because the flat surface area attracts sunshine which then penetrates into the home below.
  • On the likes of apartment buildings, a flat roof offers a whole new space. It can be used as a patio, garden, outdoor swimming pool or just a communal outside area.
  • Constructing a flat roof usually takes less time and uses less materials than a traditional roof, which means it costs less to install.

What are the disadvantages of a flat roof?

  • Maintenance is a real factor when considering whether to install a flat roof, as they require a lot of it.
  • The average lifespan of a flat roof is only 10 years, and that’s only if it is properly maintained.
  • They can develop cracks if walked on, which may cause leaks.

What types of flat roofs are there?

Any material used to construct a flat roof must be watertight, because even though flat roofs are built on a slight incline, they are still very susceptible to leaks. That said, there are five main types of flat roof: roll asphalt, single-ply, multiple-ply, modified ply, modified bitumen and flat-seamed metal.

  1. Roll asphalt flat roof

Roll asphalt is made up of layers of asphalt-coated fiberglass, tar, felt and water resistant materials, all of which are kept in place with nails or asphalt cement. The top layer is covered with gravel, which protects the roof from ultraviolet rays. This type of flat roof has been used for over 100 years and is generally the cheapest; however it doesn’t usually last much longer than 10 years.

  1. Single-ply flat roof

Single-ply flat roofs are made from one layer of materials that are a bit like rubber. These materials cost less, but are studier and more energy efficient then roll asphalt roofs. Usually single-ply roofs are made from EDPM, uPVC, ethylene and TPO. These are all mould resistant and low maintenance. Single-ply roofs usually last for up to 12 years.

  1. Multi-ply flat roof

This type of flat roof is made up of lots of layers of fiberglass, which is packed between layers of asphalt. The big benefit of multi-ply flat roofs is that they are reinforced, so they last longer and are less likely to get damaged. They can last as long as 30 years.

  1. Modified Bitumen flat roof

Some multi-ply flat roofs use modified bitumen membrane, which is made from a mixture of polymers and asphalt which makes it flexible and water resistant. The top later is covered with gravel. These types of flat roofs could last up to 20 years.

  1. Flat-seamed metal flat roof

This is the most expensive type of flat roof, largely because it is made of metal such as copper and stainless steel. Metal flat roofs usually last between 20 and 50 years.

How Much Does A Flat Roof Cost

The price of flat roof replacement in the UK depends on factors like:

Flat roof specifications: Each job is different and presents different difficulties.

How accessible is the roof: The height of the roof and whether scaffolding is required or not.

The location: If the cost of living is significantly higher, then you should expect the charges to be higher too.

Tradesman Mark Up: Each business needs to make a profit. Also, if a tradesman has a very good reputation and is very busy, the prices are usually higher as they can choose the jobs at a certain extend.

The size of the project: For small projects the cost is usually higher per square meter, due to time saving and man power considerations.

Flat Roof Prices
Job TypeCost Per Square MeterSpecifications
Felt Roof£40 -£50 + £40 if the boards are damagedThis is a modern felt roof or built up felt roof. It is also known as Torch-on flat roof.
Rubber Roof£80 + additional cost if the boards are damagedA  Modern Flat Roof similar to a firestone that is also known as E.P.D.M.
Fire Glass£90 (trims and lead flashing included)A modern fibreglass GRP flat roof system with specialised roofing grade resins.Price does not include over boarding with OSB which is absolutely necessary to adhere a new fibreglass roof to it.
Fire Glass Bay Roof£250 £490 + 50 (stripping and insulating)Even though the size is really small, the cost increases due to trim cost and time spent fitting.For approximately additional  £50 the window can also be also stripped and insulated
Lead Bay Roof£300 + lead costsPrices can vary significantly due to different project specifications and the many different options of lead code and cost of raw material.


Householder’s Guide to Flat Roofing – NFRC – http://www.nfrc.co.uk/docs/default-source/form-protected-documents/householders-guide-to-flat-roofing-2015.pdf?sfvrsn=2

The problem with flat roofs – http://www.telegraph.co.uk/finance/property/advice/8601078/Property-advice-The-problem-with-flat-roofs.html

Flat Roof – https://en.wikipedia.org/wiki/Flat_roof

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