How Much it Costs to Replace a Flat Roof in London

A roofer installing a flat roof

Let The Page curate you a bespoke shortlist of roofers suited to you and your job.

March 26, 2024

There are some home improvements that you do solely to improve the appearance of your home and some that you do out of necessity. Replacing a flat roof is one home improvement that falls into both categories.

Not only does replacing a flat roof improve the visual and curb appeal of a property, but it benefits the home by providing improved protection against weather elements, reducing the risk of leaks and structural damage, and potentially lowering energy costs.

If you are interested in finding out flat roof replacement and repair costs in London, you have come to the right place. Below, we have gone through the various costs involved – such as buying roofing materials and factoring in complexities such as having a pitched roof – to help you accurately budget for your roof replacement project.

Average Costs for a Flat Roof Replacement in London

It’s hard to give an exact flat roof cost for a replacement in London, as there are so many variables, all of which impact the cost. But, looking at the average cost can give you a good idea of how much you should expect to spend. You can then organise your budget, knowing that you have enough to see the job through to completion.

On average, you should expect to pay between £1,000 and £5,000 for a new flat roof in London, depending on the size and roof material. For example, the average cost for a flat roof on a one-bedroom flat is between £1,500 and £3,000. But, this is likely to be a lot higher on a larger property, and properties with a large roofed area.

For the main roof of a property, the average cost of a replacement is between £1,500 and £4,500. The cost is a lot lower for smaller areas, such as an extension roof, which tends to cost between £500 and £3,000. For a small porch roof, the cost drops once again, to between £300 and £600. The average cost to replace a flat roof on a double garage is between £1,200 and £2,000.

Average Hourly and Day Rates for Roofers

When you are budgeting for your roof replacement project, you should expect to pay between £220 and £320 a day for a professional roofer. If you are looking to hire a roofer on an hourly basis, you should budget between £30 to £40 per hour. This rate is likely to be slightly higher in London and other urban areas, where labour costs are typically more expensive.

Factors That Affect Costs

It’s hard to give an exact cost for replacing a flat roof in London, as there are a number of variables to take into account. Roofs can vary in shape, size and complexity, and each job is quoted on a bespoke basis. When you are considering the cost of replacing a flat roof, factors such as roofing materials and insulation all need to be factored in.

A roofer waterproofing a flat roof

Roof Type

The type of flat roof you have will greatly influence the cost of replacing it. Roofs can vary hugely, with each having its own unique requirements. Some flat roofs might require a lot of labour and materials, whereas others might be relatively straightforward. This is why it’s important to talk to a tradesperson for an exact quote, as they will tailor the cost accordingly.

Roof Size

The size of the roof directly impacts the cost of materials and labour. Unsurprisingly, larger roofs require more materials and they tend to take longer to replace, leading to higher overall costs. If you have a relatively small roof, you’re likely to find the job will be more budget-friendly and affordable.

Roofing Materials

Your choice of roofing materials will also significantly affect the cost. There are a wide range of materials, ranging from budget-friendly options to premium, high-quality alternatives. Each material differs in terms of price, durability and aesthetic appeal. This can impact the overall cost of the project. Though high-quality roofing materials cost more to begin with, they tend to last a lot longer, and could therefore save you money in the long run.

Roofing System Complexity

The complexity of your roofing system – such as its design, angles and features – will impact the cost. Features such as skylights, chimneys and dormers can make the project more complex, which increases the cost of labour and materials. More intricate roofs require additional time and expertise to install properly, and a roofing contractor’s quote will reflect that.

Roof Condition

The condition of the existing roof can impact replacement costs. If anything below the roof is damaged or rotting, or if there has been extreme wear and tear or water damage, it might need to be repaired or replaced before installing the new roof itself. This will add to the total cost. Plus, removing old roofing materials and disposing of them can also increase the cost, especially if there are multiple layers to remove and a large skip is needed.


If you need to add or upgrade the roofing insulation during the replacement process, this will cost more. However, it can also lead to long-term savings by making the roof more energy efficient. Effective insulation helps to regulate the temperature inside the home, reducing heating and cooling costs. This means that insulation is usually a worthwhile investment and one that most roofers will recommend.

Additional Features

There are a handful of additional features that will increase the cost of a flat roof replacement in London. Ventilation, guttering, underlay and protective coatings are all charged as added extras. These features are designed to increase the lifespan and performance of a new roof.

As you can see, there are a lot of things that impact the cost of a roof replacement in London, which is why it’s important to ‘shop around’ and compare quotes from a range of roofers. Once you have a handful of quotes, you will be able to determine which are too high, and if any are suspiciously low.

Costs Breakdown

When you are researching how much a flat roof replacement in London will cost, it’s a good idea to ask for a cost breakdown. This will highlight how much of your budget is being used on roofing materials, skip hire, scaffolding hire and labour. This will help you to reduce the cost if you need to, and it’s beneficial if you want to negotiate with your chosen tradesman.

Roofing Materials

The roofing material that you choose will directly impact the cost of your flat roof replacement. For example, if you choose one of the more affordable options such as felt, you should expect to pay around £40 per square metre. The average cost for a rubber roof and tiles are a similar price per square metre, at £45 and £50 respectively.

The cost will increase if you opt for a higher-quality material. For example, the average cost for a slate roof is £60 per square metre, and lead is £80 per square metre. The most expensive roofing material is fibreglass, which costs an average of £90 per square metre.

Scaffolding Hire

The average price of scaffolding hire for a flat roof replacement project is between £900 and £1,000. This will be slightly higher for larger projects, with more work and waste removal.

Old Roof Removal

The cost of removing an existing roof can vary, costing between £900 and £2,500 depending on the size and complexity of the task.

New Roof Installation

The cost of flat roof installation for a new roof varies hugely, but you should expect to pay between £200 and £500 in labour fees. You will then need to add on the cost of materials, skip hire and scaffolding hire.

Skip Hire

When you are having a new roof installed, you will need to hire a skip to remove the existing roof and any additional waste. On average, the cost of hiring a small skip is between £100 and £300. But, a larger skip will cost more, at around £400 to £500.

Additional Costs

Of course, there are additional costs to think about when you are having a flat roof replaced. One of which is the cost of cleaning the guttering, which might need to be done before your chosen roofer begins any work. Cleaning the debris out of guttering costs between £100 and £300, depending on the size of the property and the amount of guttering.

DIY Vs Hiring a Professional

When it comes to replacing a flat roof in London, you have two options. You can choose a DIY approach, or you can opt to hire a professional roofer. There are pros and cons of each.

The Pros and Cons of DIY Roofing

  • Cost Savings – A DIY approach to replacing a flat roof in London can save you money, as you won’t need to pay for labour. However, as your skills are unlikely to be at the same level as a professional, there’s a chance of a mistake being made. This could be costly to fix, limiting the amount of money you actually save by doing it yourself. You will also need to pay for materials and tools, and these quickly add up.
  • Time Commitment – There’s no denying that replacing a roof is time-consuming, and DIY projects tend to take longer than those completed by professional roofers. Unless you have a lot of time on your hands, replacing a roof is likely to impact your other commitments, such as work and hobbies.
  • Skill and Experience – Unless you have a lot of experience with roofing projects, and you are confident in your abilities, you could be lacking the skills needed to replace a flat roof. Flat roof replacements can be difficult to replace due to drainage and the need for specialist techniques. Without professional expertise, the quality of the replacement is unlikely to be up to the standard of a roofer.

The Pros and Cons of Hiring a Professional Roofer

  • Expertise – Professional roofers have the training, knowledge and experience needed to handle even the most complex of flat roof replacements, and they can do so efficiently and effectively. They know the best materials and techniques for the job, and they can overcome challenges along the way.
  • Time Saving – When you hire a professional to replace your roof, you are likely to save a lot of time. Instead of having to fit in doing a roof replacement around other commitments, you can simply hand everything over to a professional. They can complete the project quickly and with fewer disruptions to your daily life.
  • Safety – Replacing a flat roof means working at a height, which can be dangerous without experience. Roofing professionals are trained to safely work on roofs, and they have the necessary equipment to work at heights safely and without risk.

Planning Permission

When it comes to replacing a flat roof in London, you need to think about planning permission.

The need for planning permission for a new roof depends on a variety of factors, such as the type of property and the extent of the changes. Usually, routine maintenance and repair work to existing roofs – such as replacing tiles or repairing gutters – don’t require planning permission. This is because minor repairs don’t change the roof’s appearance in a big way.

However, if you are replacing the entirety of a flat roof and it involves substantial alterations to the roof’s structure, you might need planning permission. Planning permission might also be required if the building is listed, or if it’s subject to local planning restrictions. Before you begin replacing a flat roof, it’s a good idea to find out if planning permission is required for your exact plans.

Finding a Roofer in London

Two tradesmen by their van

There are various ways to find a roofer in London, meaning that finding the right tradesman for you tends to be a simple and straightforward task. You can use The Page, search online or ask friends and family.

The Page

With The Page, finding the right roofer for your project is a simple process, one that has been designed for your convenience. All you need to do is submit an inquiry detailing the specifics of your roofing requirements, and The Page will match you with a curated list of skilled tradesmen in London, all of whom are willing and able to take on the job.

Let The Page curate you a bespoke shortlist of roofers suited to you and your job.

All of the tradesmen on The Page have undergone a vetting process, to ensure that they can provide a high quality and professional roofing service. They have been met with, vetted and assessed, and their work has been reviewed. This means that you can choose any roofer on The Page, knowing that you are guaranteed a reliable and expert service.

Online Search

Finding a roofer in London can be a straightforward process if you know where to look and what to consider, and an online search is one of the quickest ways to do so.

This is easily done using search engines; with a quick search of “roofers in London,” you will be given a list of roofing experts in your local area. You can also use review websites and The Page, to see which roofers other people have had good experiences with.

Ask Around

You can also ask friends, family and neighbours for roofer recommendations. They can provide valuable reviews based on their personal experiences with a tradesman, providing insight into the quality of a roofer’s workmanship, professionalism and customer service.

By asking around, you gain access to a pool of trusted referrals, which can save you a lot of time and effort when it comes to researching potential contractors.

There’s a lot that goes into the cost of replacing a flat roof in London but, with the right amount of research and planning, you can budget accordingly.

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