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myFlat Roof Replacement Cost Calculator
Flat roofs have many benefits, being cheap to install and easy to access when you need to repair your roof.
But, with a shorter lifespan than traditional pitched roofs, you'll often need to factor in a flat roof replacement cost after the first 15 years.
This is due to the shallow pitch of flat roofs, making them prone to water pooling after heavy rainfall.
If left untreated, this can cause the flat roof's surface to sag, and can lead to much bigger problems such as damp, mould, and major leaks in your home.
So, how much does it cost to replace a flat roof?
The average flat roof replacement cost is around £2,500.
But, to get an accurate quote bespoke to your situation, you can use our flat roof replacement cost calculator.
Ready to give it a go?
How to Use the Flat Roof Replacement Calculator
To get your flat roof cost, all you need to do is:
- Enter your roof size
- Choose the roof material (e.g. EPDM, felt, fibreglass)
- Enter your location
And our flat roof replacement cost calculator will create an estimate for you, based on average flat roof replacement costs in the UK.
Get started with your flat roof replacement now!
Flat Roof Replacement Cost Calculator
Table of Contents
Average Flat Roof Replacement Costs
The cost to replace a flat roof is £2,500.
But, this figure can change depending on the following:
- Roof size and shape
- Type of flat roofing material
- The type of structure (e.g. extension, garage roof, porch)
- Ease of access to your roof
- If the old roof contains asbestos, making the removal process more complex
To put those factors into context, here are some estimated flat roof replacement prices for different-sized structures:
| Description | Cost |
|---|---|
| Standard flat roof replacement | £2,000 – £6,000 |
| Extension roof | £800 – £3,500 |
| Double garage | £1,600 – £4,500 |
| Single Garage | £1,000 – £2,200 |
| Dormer | £900 – £1,800 |
| Porch | £400 – £1,200 |
Flat Roof Cost Calculator Breakdown
Your flat roof material directly impacts the price you pay for roof replacement.
This is how much different types of flat roof materials cost per square metre.
- Felt flat roof cost — £80 to £120 per m²
- Rubber flat roof cost — £110 to £160 per m²
- Fibreglass flat roof cost — £120 to £180 per m²
(This includes material and labour charges.)
Depending on your situation, you may also need to budget for the following:
- Scaffolding hire costs - If you need this, the cost of hiring scaffolding will typically land between £800 and £1,200 for a flat roof replacement.
- Asbestos removal costs - If your roof was built or modified pre-2000, it may contain asbestos. This requires specialist testing and removal, which costs around £60 per m².
Ready To Get a Quote?
MyJobQuote can also help you find local roofers today!
Get free, no obligation quotes from local flat roofers who can handle all of this for you. MyJobQuote is fast, easy, and connects you with professionals in your area.
All you need to do is submit a few basic details about what you’re after, and we’ll handle the rest.
Factors That Impact Flat Roof Replacement Costs
There’s no one-size-fits-all for the cost of replacing a roof, and flat roof replacement costs can vary hugely depending on several key factors.
Here's what you need to know:
Roof Size and Shape
The larger the roof, the higher the cost of replacement.
This isn’t just because more materials are needed - it’s also due to the increase in manual labour. Unique-shaped roofs or those with multiple complex sections tend to require more time and expertise, which increases the final price.
Type of Material Chosen
There are different flat roofing materials to choose from, all of which have slightly different price points and lifespans.
Your roof material choice will impact both the immediate cost of the replacement and the long-term value, depending on how durable it is.
Ease of Access and Location
If a roof is difficult to reach, it’s going to cost more to replace.
This includes flat roofs on tall buildings and those with limited surrounding space, as scaffolding could be required, and this comes at an additional cost.
Flat roof costs also vary depending on where you live in the UK, with busy cities like London having higher prices than more rural areas.
Removal of Old Roofing
If your old roof needs to be taken away before the new one can be installed, this adds time and labour to the job, which will increase the flat roof cost.
The condition of the existing structure may also affect the cost, depending on whether additional repairs or preparation work are needed.
Urgency of the Job
Of course, not all flat roof replacements are planned. If you find yourself needing an emergency replacement or repair, you'll likely be charged more for the speedy service.
This could be the case if you’re dealing with an active leak, or major storm damage. You should expect to pay more for urgent and out-of-hours work.
How to Lower Flat Roof Replacement Costs
Here's what you can do to keep your flat roof cost down, without having to compromise on quality.
Get Multiple Quotes
It’s a good idea to get at least 3 quotes from local roofing experts to give yourself a good idea of what people are charging.
This not only helps you to find the best price for a roof replacement, but it also gives you an insight into average rates for the local area.
Choose the Right Timing
You don’t always have the luxury to choose when to replace a flat roof, especially if it’s in need of urgent repairs.
But if you do, try to avoid scheduling work during peak times when roofers are in high demand. Not only do off-peak periods offer better availability and flexibility, but you might even benefit from slightly lower labour rates.
Bundle Similar Jobs Together
You might find your flat roof needs replacing at the same time as other jobs, such as gutter replacement or insulation upgrades.
You might be able to combine these tasks into one larger project, which can result in a lower overall cost, compared to booking them separately.
Use Cost-Effective Materials
Though premium materials - such as fibreglass - have a higher upfront cost, they often require less maintenance and last longer than cheaper alternatives, making them a cost-effective investment in the years to come.
It’s important to find a balance between choosing a cost-effective roof material, and one that’s going to last as long as possible.
When to Replace Your Flat Roof
Knowing when to replace your flat roof is important, as you don’t want to leave it too long and let the problem worsen, nor do you want to replace a perfectly good roof too early.
Signs of Wear or Damage
Here are the common issues you need to look out for with flat roofs:
- Visible cracks
- Sagging roof surface
- Frequent leaks
- Water pooling
- Struggling to drain
These are all signs that your flat roof may need to be replaced. Leaving these issues can lead to expensive structural damage over time.
If repairs are becoming a regular occurrence, full replacement may be a more cost-effective option.
Lifespan of Common Flat Roofing Materials
Every roof material has a typical lifespan.
For example, traditional felt roofs usually last around 10 to 15 years.
EPDM can last for much longer - up to 50 years if well maintained.
If your roof is nearing the end of its expected life, and it’s showing signs of wear, it might be time to start planning a replacement.
Why Proactive Replacement is More Cost-Effective
Waiting until your flat roof fails completely often results in emergency repairs, water damage and interior issues, all of which are likely to be more expensive than planned roof replacement.
By being proactive, you have more time to choose materials, compare flat roof costs, and schedule work at a convenient time.
