Flat Roof: Repair Or Replace?

Flat roof looking worse for wear? Wondering if you should look at flat roof repair or go for a full replacement? How do you even know when your roof is in need of attention?

As far as roofing goes, flat roofs are effective and long-lasting, but like all things, they eventually become victims of old father time. Common problems can occur with leaks, moss and weathering; if ignored or unnoticed, you can end up with a far more significant problem.

Knowing whether your problem requires repairing or replacing your flat roof can be difficult. But a little knowledge can go a long way, so we’ve written this blog to give you everything you need to know about flat roof repair so that you can make an informed decision.

Types Of Flat Roof

First things first, what type of roof do you have? 

To find out whether you need flat roof repair, you need to know what kind of roof you’re dealing with. Your roof structure can impact a few factors when it comes to repairing or replacing, like risk, cost and difficulty. 

Take a look at the three types of flat roofing and see which one sounds most like yours.


A BUR is a Built-Up-Roof. This is a roofing system that uses layering to create a strong and durable roof. Various materials are built on top of each other in a method that’s been used for over 100 years. It’s a tried and tested system, though we’ll admit the materials used have been updated over the years for a longer-lasting result.


A Modified Bitumen Roof – or MBR – is a commonly used alternative to traditional built-up roof styles. To get its flexible quality it’s made of asphalt lined in a mineral topcoat. Usually, it’s part of a two or three-layer system to make sure it stays watertight for longer. 


Used worldwide, EPDM (ethylene propylene diene terpolymer, quite the mouthful we know) has grown in popularity recently. It’s an extremely secure and reliable solution for flat roofing, because of its easy and quick installation and durable finish. 

Now you know what type of roof you have, you’re armed with the knowledge you need to prepare for that looming repair or replace decision. 

But hold on – how can you tell if your flat roof is even in need of repair to start with? Well, your roof will certainly let you know when some noticeable problems start appearing.

Common Flat Roof Repair Problems

Of course, if your roof is falling in and you stay drier outside than in, you’d know it was time for a new roof. But the signs that you need some flat roof repair help can be a bit harder to spot, especially since you probably don’t go up a ladder to inspect your roof every week.

The most common culprits for roof damage and wear are also the clearest indicators that you should think about repairing sooner than later. 


Leaking is most often the result of damage to the membrane layer of your flat roof. The damage level can vary in severity but the more leaks you see, the more damage is likely. Some tears are easily repaired or patched but bigger areas might be more cost-effective to replace.

Pooling/Ponding Water

Water pooling is a result of an uneven flat roof surface. In most cases this defect can be repaired, but if left too long bigger problems can rear their head, which might be more expensive and end up requiring a full replacement.


Moss, Algae and Plant Growth

The growth of all things green or gooey is the result of dampness. This is a bad problem to have because it encourages bugs, pests and birds to come up and nest or feed. This growth holds water so it can add weight on your roof, but maintenance can keep it at bay altogether.


Cracking of your top membrane layer is usually the result of weathering after constant UV rays and extreme temperatures. It can lead to water ingress, leaks, and further damage of your flat roof structure. Repair is your best choice if the area is small, but replace if it’s big.


What’s The Cost Of Flat Roof Repair?

As you might expect, flat roof repair is cheaper than replacement, but depending on the scale of damage you’re dealing with, it can be more cost-effective to replace.

Factors to consider when you’re choosing between flat roof repair or replacement are…

  • The size of the problem – big and small problems both require quick action, to prevent the situation from worsening and taking the choice out of your hands.
  • Type of repair – there are lots of options to fix a flat roof including EPDM, PVC, mastic asphalt and more, and each method has its own costs, difficulty and results.
  • Cost – a lot goes into the cost of your repair, like scaffolding if required, materials, labour, insurance – and not forgetting that quality work is worth a higher investment.

While replacement can set you back considerably more, the price of flat roof repair also has a lot of dependent factors. From the size of your roof, to the material of your roof and the method being used to fix it, there’s a lot that goes into the cost. 

Now, we can’t give you an exact price (unless you get in touch for an accurate flat roof repair quote), but generally speaking, you can pay anywhere from £800 – £1400 for your flat roof problems to be solved. 

Should You Repair Or Replace Your Flat Roof?

It’s the big question. Repair or replace? Replacing your flat roof is likely to cost you more, and repairing an issue before it gets worse is always the ideal solution. In most cases, common problems can be resolved through repair and ongoing maintenance. 

While you might be tempted to DIY your repairs, it’s worth getting a price from our flat roofing experts, and getting the job done right the first time.


Request a
Free Quote

If you’d like to discuss a project you have we’d love to help.

Call us today on 01384 891341 for a free no-obligation quote.

Related Articles


  Cut edge corrosion is one of the most prolific cladding problems we see at...

worker chemical protection suit spraying disinfectant public surfaces

When it comes to commercial and industrial building maintenance and protection, on-site spraying has rapidly...

hands engineer working blueprint construction concept engineering tools vintage tone retro filter effect soft focus selective focus

Investing in commercial property for renovation has become a popular way for investors to earn...