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myBay Window Roof Replacement Cost
At a Glance
- The average cost of a bay window roof replacement is around £980.
- It will take approximately 1 to 3 days to complete this type of job.
- A breakdown of how much a bay window roof replacement typically costs in 2026.
- How long it takes to replace a bay window roof and what's involved.
- How to find a local bay window roof replacement contractor using MyJobQuote.
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Looking into the cost of replacing a bay window roof in 2026?
If your bay window roof is damaged, leaking, or worn, it may be time to consider a replacement.
Bay window roofs are flat or pitched and covered using lead, fibreglass, EPDM rubber, tiles or felt, and although a bay window roof is a small roofing job, it is important that it's done properly to prevent water penetration, withstand high winds, and last for many years.
Read on to learn more about bay window roof replacement costs.
£980
Table of Contents
- How Much Does Bay Window Roof Replacement Cost?
- Labour Costs and Timescales for Bay Window Roof Replacement
- Supply Costs of Bay Window Roof Replacement
- Additional Costs of Bay Window Roof Replacement
- What Impacts the Cost of Bay Window Roof Replacement?
- Types of Bay Window Roof
- Checklist: Hiring Contractors for Bay Window Roof Replacement in the UK
- Removing an Existing Bay Window Roof
- FAQs
How Much Does Bay Window Roof Replacement Cost?
The cost of replacing the roof on a typical bay window will be between £350 and £2,350. The total costs will depend on a number of factors, such as the size of the window, roofing material, local roofer's rates, and any challenges with the design of the window or access.
The typical cost of a straightforward roof replacement on an average-sized bay window is £980.
Which material are you considering for your bay window roof replacement?
Felt
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Fibreglass
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Slate tile
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Lead
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Bay Window Roof Price List
The table below shows the typical costs for a bay window roof replacement depending on the roofing material used and the size of the job. It's worth mentioning that these costs will increase if there is any additional work required, such as repairing or replacing the roof deck or renewing fascias and soffits.
| Material Type | Small Bay Roof (2m²) | Medium Bay Roof (4m²) | Large Bay Roof (6m²) |
|---|---|---|---|
| Felt | £350–£410 | £450–£570 | £550–£730 |
| EPDM Rubber | £410–£450 | £570–£650 | £730–£850 |
| Fibreglass | £490–£610 | £730–£970 | £970–£1,350 |
| Slate Tile | £890–£1,200 | £1,100–£1,700 | £1,250–£2,200 |
| Lead | £980–£1,250 | £1,250–£1,800 | £1,550–£2,350 |
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Bay Window Roof Replacement Prices per m²
The type of roofing material used to replace your bay window roof can have a big impact on the total cost of the project. The average installed cost of bay window roof replacement per m² is £120, but the table below shows how the different roofing materials affect this price.
| Roofing Material | Installed Cost per m² | Typical Lifespan |
|---|---|---|
| Felt | £50–£80 | 15 to 20 years |
| EPDM Rubber | £80–£100 | 25 to 35 years |
| Fibreglass | £120–£180 | 35 to 50 years |
| Slate Tile | £95–£275 | 80 to 150 years |
| Lead | £140–£250 | 50 to 100 years |
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Labour Costs and Timescales for Bay Window Roof Replacement
Labour costs account for a good proportion of a bay window roof replacement. Bay window roof replacements can usually be carried out by a roofing specialist who typically charges between £200 and £275 a day.
However, if you're replacing your roof with lead or slate, you'll need a specialist roofer who will charge a higher day rate.
Bay Window Roof Replacement Labour Costs
The table below shows how the type of roofing material and size of your project will affect the labour costs of getting a bay window roof replaced.
| Roofing Material | Typical Timescale | Small Bay (2m²) | Medium Bay (4m²) | Large Bay (6m²) |
|---|---|---|---|---|
| Felt | 1 to 2 days | £200–£275 | £200–£275 | £400–£550 |
| EPDM Rubber | 1 to 2 days | £200–£275 | £200–£275 | £400–£550 |
| Fibreglass | 1 to 2 days | £200–£275 | £200–£275 | £400–£550 |
| Slate Tile | 1 to 3 days | £350 | £700 | £1,050 |
| Lead | 1 to 3 days | £350 | £700 | £1,050 |
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Where you're located in the country will also affect labour rates, as day rates for roofers in London and the South East will typically be 15% to 25% higher than other areas of the country.
Factors such as difficult access, complex window layouts, or additional repairs and replacements will also mean the job takes longer and labour costs will be higher.
Supply Costs of Bay Window Roof Replacement
There are a number of supplies required to replace a bay window roof. The cost of supplies depends on the size of the bay and the type of roof. Overall costs will increase if you include premium materials, or leadwork and/or decorative detailing.
The table below shows the average costs for the materials you might need, depending on your project requirements, and the typical cost of these materials for replacing the roof on a medium-sized bay window.
| Supply | Unit Cost | Total Cost |
|---|---|---|
| Roofing Material | £50–£275 per m2 | £200–£1,100 |
| Timber Decking | £14–£25 per board | £60–£100 |
| Plywood or OSB Boards | £24–£35 per board | £50–£105 |
| Membrane | £9–£14 per m2 | £35–£55 |
| Battens | £6–£20 each | £20–£60 |
| Flashings | £6–£18 each | £20–£70 |
| Gutter Trims | £7–£20 each | £15–£40 |
| Fixings | £9–£11 per pack | £9–£11 |
| Sealant | £4–£9 per 300ml tube | £7–£18 |
| Replacement Fascias or Soffits (if required) | £12–£40 each | £40–£120 |
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Additional Costs of Bay Window Roof Replacement
When you budget for a replacement bay window roof, it is always a good idea to think about the additional costs that might come up as a result of the work. For example, once the roof covering has been removed, you might find the decking has rotted or is sagging, insulation needs improving, or you need to fix areas where there is water damage.
Other additional costs include waste disposal if they are not included in the quote, skip hire and scaffolding if the roof is at height. You might also need to replace soffits, facias or guttering. Being aware of additional costs will help you to work out your budget more efficiently and avoid any unexpected expenses once the work is in process.
Typical additional work on a bay window roof includes:
| Additional Work | Description | Average Cost | Duration |
|---|---|---|---|
| Timber Deck Replacement | Fit new OSB or plywood timber decking | £25–£35 per m2 | 3 to 6 hours |
| Timber Deck Repairs | Carry out repairs to rotting or sagging panels | £20–£30 per m2 | 3 to 4 hours |
| Lead Flashing Replacement | Fit new lead flashing where necessary | £200–£425 | 1 to 2 days |
| Waste Removal | Collect and dispose of all old roofing material using a skip or van | £200–£400 | Often included in a quote |
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What Impacts the Cost of Bay Window Roof Replacement?
There are several factors that influence the overall cost of a replacement bay window roof. The main consideration is the size and shape of the bay and whether it is curved or ornate, which will require more experienced workmanship.
The roof material will also have an effect on the final price. If you are on a budget, then felt is an affordable option. If you have a lead roof and you want to replace it with lead again, then you will be paying for a premium material and higher labour costs due to the specialists' skills needed for installation.
Other factors include:
- Amount of timber repair.
- Whether extra insulation is applied.
- The need for scaffolding.
- Complexity of flashing work.
- Whether roofing materials need to match the rest of the property.
- Ease of access.
- Whether internal damage caused by leaks needs to be repaired.
- Regional labour rates.
One of the most important things is to deal with any underlying issues. If these are ignored to save money, the roof covering won't last its lifespan, and you may end up spending even more on repairs and another bay window roof replacement.
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Types of Bay Window Roof
Many householders choose to replace their bay window roof covering with like-for-like material. But you can change the roof covering if you prefer the appearance of another material, or you need to match the covering to your budget. Common bay window roof coverings include:
Felt Bay Window Roof Cost
Felt is one of the cheaper materials and is popular as a covering for flat roofs. It is durable, but it has a shorter lifespan than other types of material. Installation is usually straightforward, as felt can be shaped into any awkward angles.
Cost: £50 to £80 per m2
Lifespan: 15 to 20 years
Lead Bay Window Roof Cost
Lead was the traditional covering for bay window roofs. They can last a lifetime, and they look beautiful. Lead isn't cheap, and it may also be difficult to insure because it is now a target for thieves who sell lead for scrap.
Cost: £140 to £250
Lifespan: 50 to 100 years
Slate Tiled Bay Window Roof Cost
Slate is the traditional tile used for a bay window roof. It is strong and durable, easily withstanding UK weather conditions, and it is also very attractive. However, it is complex to fit, so you will need an expert installer, and the cost of the slate is high.
Cost: £95 to £275 per m2
Lifespan: 80 to 150 years
Fibreglass Bay Window Roof Cost
Fibreglass is becoming the modern alternative to lead as a bay window roof covering. It is extremely durable, and it can be installed in various designs and colours.
Cost: £120 to £180 per m2
Lifespan: 35 to 50 years
EPDM Rubber Roofing Bay Window Roof Cost
EPDM rubber roofing is often used on flat roofs. It is highly waterproof and low-maintenance. But it doesn't have the aesthetic appeal of other roofing materials.
Cost: £80 to £100 per m2
Lifespan: 25 to 35 years
You can also change the shape of the roof. It can be pitched or flat.
Pitched Bay Window Roof Cost
Pitched bay window roofs are usually found on period homes and traditional builds. They are often covered with slate tiles or lead. Pitched bay window roofs tend to deal with water drainage better than flat roofs and offer a longer lifespan.
Cost: £95 to £275 per m2
Lifespan: 80 to 150 years
Flat Bay Window Roof Cost
Flat bay window roofs are cheaper to install than pitched ones, and often you can use less expensive materials like felt, fibreglass or EPDM rubber as a roof covering.
Cost: £70 to £125 per m2
Lifespan: 15 to 30 years
Checklist: Hiring Contractors for Bay Window Roof Replacement in the UK
When you post your bay window roof replacement project on MyJobQuote, you will get at least 3 quotes from local roofing specialists in your area. Although it is tempting to go for the cheapest quote, make sure you compare each one to check what is and isn't included. A cheap quote can often lead to additional costs once the work has begun.
Before hiring a roofing contractor, consider using the following checklist:
- Does the contractor have experience replacing bay window roofs?
- Are they specialists in slate or lead roofs (if required)?
- Do they have samples of previous work and feedback from satisfied customers?
- Is waste removal included in the quote?
- Can they provide a separate quote to give you an idea of what costs would be if new decking or insulation needs to be installed?
- How much would new fascias and soffits cost?
- Is scaffolding included (if required)?
- Do they have up-to-date public liability insurance?
- Is the work guaranteed?
Also, make sure the quote is in writing and covers the complete scope of the work as well as pricing for materials and labour.
Removing an Existing Bay Window Roof
Before a new roof is installed, the old roof covering will be removed. The process is usually as follows:
- Strip back the original roofing cover or remove the lead or tiles.
- Check the timber underneath for damage. If the decking is damaged, it will need to be removed and replaced or repaired.
- Check insulation and improve if necessary.
- Lay new roofing material and ensure all joints are watertight.
FAQs
Is It Better To Repair or Replace a Bay Window Roof?
A reliable bay window roofing contractor should be able to advise you exactly what you need. Usually, if you only have minor damage and the roof is less than 10 years old, then a repair should solve any problems.
If, however, the decking beneath the material is rotten or you have widespread leaks, then a replacement is probably advisable.
If, however, the decking beneath the material is rotten or you have widespread leaks, then a replacement is probably advisable.
What Type of Covering Is Best for a Bay Window Roof?
The type of bay roof covering you want will depend on your budget. If you have a large budget and you want a material that looks attractive and is long-lasting, then you can choose lead or slate. If your budget is restricted, then felt or rubber are cheaper options that will still do the job and last more than 10 years.
Is a Bay Window Roof Replacement Worth the Budget?
If your bay window roof is old and you are having problems with water ingress, then a new roof will improve your home's appearance and solve any problems, such as damp caused by water coming through the roof.
If your budget doesn't stretch to using the same roof covering, you can opt for something cheaper that fits your budget.
If your budget doesn't stretch to using the same roof covering, you can opt for something cheaper that fits your budget.
Do I Need Planning Permission or Building Regulations Approval to Replace a Bay Window Roof?
No. With a like-for-like replacement that doesn't change the roof's appearance or structure you don't usually need planning permission or Building Regulations approval. However, if you live in a listed building or in a conservation area, or the replacement roofing material means structural work is required, approval may be required. If you're not sure, check with your local authority.
How Long Does It Take To Replace a Bay Window Roof?
A straightforward installation will usually take a day. If you have awkward angles or shapes and the roof covering is in lead or slate, then it might take a day or so longer to complete.
Can I Replace a Bay Window Roof Myself?
It isn't recommended that you replace a bay window roof as a DIY job. It is very labour-intensive. You may need additional work once the covering has been stripped away and materials like slate and lead need to be installed by experienced professionals. Other materials require special tools, and you may also need to work at height, which is dangerous.
A bay window roof installer will have the appropriate equipment and the necessary skill and experience to replace your bay window roof professionally.
A bay window roof installer will have the appropriate equipment and the necessary skill and experience to replace your bay window roof professionally.
