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How much does a new flat roof cost?


Are you wondering if you need to replace your flat roof and considering what would be the best option for you and how much does a new flat roof cost? Most old flat roofs are still installed with felt roofs, Redline, however, has the perfect solution for your garage, shed, summer house or workshop, or maybe even for your tree house or garden roof with the new rubber roofs.


New technology of rubber flat roofs


The purpose of a flat roof is to protect the structure from the weather, our EPDM flat roofs are not only weather resistant they are also cost effective, durable and sustainable. With our 30 years experience of installing flat roofs, we consider these as vastly superior to traditional felt roofs. EPDM stands for Ethylene Propylene Diene Monomer, a synthetic man-made rubber membrane. This exciting innovation in flat roof technology has so many advantages over a felt roof.


Traditionally felt flat roofs are made using harsh chemicals and toxic adhesives, and involve three layers of board, tar and often crushed slate, which puts extra weight on top of a small structure. Felt roofs have to be maintained and repaired regularly, as they do not with-stand well the harsh Lancashire weather, and all of the old materials end up in landfill. EPDM roofs provide a lightweight rubber membrane that offers really effective waterproofing properties that don’t become compromised by a heavy Northwest downpour, unlike the traditional felt roofs.


Can a rubber roof really be sustainable?


These rubber roofs are also good for the environment and sustainable as they are made from recycled rubber discarded during the tyre making process. They are also 100% recyclable when it comes to the end of the roof’s long life. With the process of installing EPDM there is no need for toxic adhesives and chemicals and it is pollution free. Therefore, the gutter system with the rubber roof can provide a non-toxic solution to gathering rain-water in a water butt or barrel, for your vegetable garden or flowers. The roof also provides the perfect waterproof base for growing a garden roof with grasses or moss, which as well as being attractive provides an extra layer of insulation. The roofs are also fire-resistant, and unaffected by cold, heat and UV light; plus the EPDM system is BBA certified, so when you are considering the cost of a new flat roof for your building you know you are investing in a quality sustainable product.


The cost of a new flat roof is dependent on a variety of factors


EPDM roofs are cost effective, particularly as they last such a long time, but the cost of a new flat roof is going to depend on how big the surface area is, how easy it is to remove the old felt roof, and the height of the building. There might need to be an added cost of scaffolding if it is on a tall structure, but generally flat roof buildings are one storey and so installation is straightforward and easy.


How do I know when I need a new flat roof?


The first thing to consider if you’re not sure whether you need a new flat roof is when was your roof originally installed? However, the expected life of a flat roof can be dependent on the materials and method used and the competence of the installer. If the roofer when installing your flat roof tried to cut corners on materials or time, this might have compromised its long-term resilience and durability. Equally if the roof has not been properly cared for and maintained it might deteriorate quicker than it should. With the technology of flat roofs constantly evolving and improving the guarantees for performance have increased. Our EPDM roofs are guaranteed for 20 years and have an expected lifespan of many more. The trend for rubber roofs took a while to catch on in the UK, whereas it has been used in the US since the 1970’s and many of the roofs installed then are still effective. So if you are wondering how much does a new flat roof cost you know that you are making a sound investment in your property when you install EPDM. If you want advice about a new flat roof please contact us and we will be happy to answer any  questions, we have 30 years of experience and are recognised for being efficient and professional, as you can see by our ratings of 4.8 stars on Which trusted traders customer reviews.


What are the signs that I need to get a new flat roof?


So, we have established you can’t just rely on the age of the roof as an indication of when it needs replacing, therefore it’s important to know the signs to look out for that suggest your roof is no longer weather resistant and has ceased doing its job of protecting your building. 


  • Leaks
  • Tears splits and cracks, on the surface of your roof
  • Pools of water on the surface
  • Moss
  • Bubbling and blistering
  • Exposed timbers
  • Gaps at adjoining walls and upstands
  • Damp in the interior


Act fast if you find any leaks


It might seem obvious but any water leaking into your garage or shed should not be ignored as the problem will only get worse. It can cause structural damage to your building if damp and mould infiltrate the walls, which will be costly to fix; not to mention the health risks of mould, which is known to cause allergies and cause breathing problems.


Is it a big problem if there are tears, splits and cracks on the surface of my flat roof?


Keeping an eye on the exterior condition of the roof is the easiest way to spot problems with your old felt roof. Any tears splits or cracks in the felt indicate that the covering is no longer waterproof, and if it has been like that for a while then the chipboard or ply board underneath has likely absorbed a lot of water, and the boards have probably deteriorated. This may also result in water leaking through to other parts of the structure, creating damp in the walls of a garage or rotting the wood of a shed. If the whole surface of the roof is covered in tears and splits then it is essential the roof is replaced as soon as possible. If it is a minor tear that you have just discovered then it is probably possible just to repair, but you have to factor in the cost of time, materials and labour to have it repaired, when you consider the alternative of having a new durable EPDM roof installed which will last for many years, and could save you money in the long run.


The high winds in the Northwest can easily damage a traditional felt roof, making it not as durable. EPDM rubber roofs are a weather resistant material and also lightweight, so they don’t put extra pressure on the structure underneath and stands up to the strongest winds.


Are pools of water on a flat roof something to be worried about?


Another thing to be mindful of when examining your flat roof for any issues, is to look for any pooling of water on the roof. If you notice water standing on the flat roof this will add extra weight and pressure onto a felt roof and can result in it splitting, which will make it vulnerable to rain penetration. There could be a blockage in the gutter or maybe the surface of your felt roof has become uneven over time.


Should I be worried about any growth on the roof?


If you discover moss lichens, or algae on your roof this indicates it hasn’t been regularly maintained and the unwanted retention of water needed for this to grow indicates that the surface is no longer weather resistant. So, finding moss growing on your roof might not seem something to be concerned about, but If this isn’t examined and dealt with immediately this could lead to more serious problems. EPDM rubber roofs are resistant to moss growing and allow the surface to remain smooth so that the water drains away.


What does it mean if I find bubbling and blistering on the flat roof surface?


If you are inspecting your roof for problems, then blistering and bubbling on the surface of your felt roof is another issue you don’t have to be an expert to discover. If you find this, it is a result of adhesion failure in the roof and the issue is that the bubbles can fill with air, or worse water. Another problem is that the bubbles may pop and cause a hole in the felt roof. This is a usually a result of there being too much moisture when the roof was installed, which could be because of poor ventilation but can also be due to bad workmanship and poor insulation.

EPDM because of its natural properties is completely resistant to blistering and cracks and in comparison to felt roofs is easy to install.


Is it a problem if I can see exposed timbers on my flat roof


If you find any exposed timber this needs to be dealt with immediately as the roof isn’t doing its job anymore and the timber is at risk of rot and deterioration which will be very costly to replace.


Examine carefully gaps at adjoining walls and upstands


When the felt roof was installed if it was not sealed properly where the roof meets adjoining walls or upstands then rainwater is leaking into the structure below. This is one of the most important things to investigate when checking your old felt roof, ensure the felt is effectively chased into the adjoining walls and sealed on upstands. This could make the difference between your roof offering effective protection against the rain and water leaking in. The felt needs to extend up the wall and be chased into the pointing, and then repointed. Unfortunately, too many cowboy builders do not take the time or effort to install correctly. If you find any damp patches or discoloured paintwork on the walls near to where the roof and the wall meet, then it is worth investigating this further before the water penetrates into the brickwork. 


Should I be worried if I find damp in the interior wall of my garage?


Any sign of damp on the walls of your garage, shed or summer house is likely to be an issue with the roof. If it is a wooden shed you might find the paint is blistering or cracking, if it is a brick wall of a garage you might notice the bricks are slightly discoloured or a shade darker than others due to the moisture in them. It is important to find where the water is coming from straight away before you have a bigger problem on your hands.


Epdm flat roofs are ideal for rural exposed locations


If you live in a more rural location in Lancashire, EPDM roofs can offer more protection to your garage roof or summer house roof when they are exposed to harsher and more unpredictable weather conditions as the rubber membrane roofing is resistant to high winds; something which is neccessary in the Lancashire countryside. It is important that the EPDM membrane is correctly attached to the roof deck to ensure it is wind resistant so it is crucial to use a company you can trust. Redline has been installing roofs in Lancashire for many years and is used to the increment weather.


Why Epdm is a great choice for replacing your bungalow flat roof in a rural area


Often you will find that bungalows and single story buildings have been extended, either outwards or upwards, this means inevitably new roofing sections have been added to the original roofing, many of these extensions are with a flat roof. If you are considering replacing the flat roof section on your bungalow EPDM is a good choice of material, particularly if your property is in a rural Lancashire location as the building will be exposed to extreme windy weather and EPDM has been shown to withstand these harsh weather conditions, being extremely wind resistant and a water repellant. Adding extra protection to your bunaglow roofing.


Epdm flat roofs are suitable for agricultural buildings


Another place where EPDM flat roofs are often installed are on farms. EPDM flat roofs are ideal for agricultural buildings including barns, sheds, and stables as they are easy to clean and are suitable for withstanding harsh Lancashire weather conditions, being wind resistant and higly waterproof.


If you still need more advice about your flat roof


We hope this guide helps you to know whether you need to think about having a new flat roof on your shed, garage or summer house. 


If you have more questions about EPDM roofs please take a look at our guides; Five reasons why EPDM is the best choice for the environment and for your roof and The advantages and disadvantages of EPDM roofs. 


We consider our rubber roofs to be a great improvement on traditional flat roof methods; providing a quick toxic free installation without any harsh solvents or adhesives. We are happy to have found a product that is sustainable yet also very durable; so the roof is good for the planet as well as for your shed, especially as they are made from recycled rubber. The roofs are so easy to maintain and are weather resistant to heat, cold and rain, whilst also being fireproof. They provide a lightweight alternative to heavy felt roofs, and the rain pours off the smooth surface so it doesn’t bear extra weight in a down pour. All in all we think the roofing system gives you less to worry about as you can trust in the expert design and installation by Redline and know that your building will be protected for years to come.


We have 30 years of experience working in Preston and all over Lancashire, and we are more than happy to discuss your requirements and give you advice and a free quote. We believe our rubber roofs are an investment as they have a 20 year guarantee, but EPDM roofs have been known to last over 40 years with the right care and maintenance.


Preston Office

Office 501
City House
131 Friargate


Leyland Office

317 Golden Hill Lane,
PR25 2YJ


Contact us:

Mob: 07903 937995
Tel: 01772 977 866

Tel: 0800 2927908
Tel: 07903 937995