Garage roof replacement

There are several things to consider when planning a new garage roof, whether it be a pitched or flat garage roof replacement. The biggest considerations are the type of roof you’re planning, the materials to use and the costs involved.

It’s also important to consider which building regulations might apply. If your current garage roof contains asbestos, then it’s recommended you consider a full asbestos garage roof replacement.

These factors apply to both pitched and flat garage roof replacements.

Things to consider when replacing a garage roof

There are several things to consider when carrying out a garage roof replacement such as:

  • The type of material to use
  • The style of roof (pitched vs flat)
  • Garage roof insulation
  • Any potential pre-existing water leakage

Consider each element because they will impact the final cost of the new garage roof and the time it takes to install.


The type of material you use will be the biggest factor that influences cost. Roofing felt is the most affordable, costing around £40 per square metre (m²) on average, as well as being comparatively easy to repair.

However, the drawback is that roofing felt tends to wear out quite easily so you may need to repair your roof more regularly compared to other roofing materials.

Alternatives such as EPDM rubber and GRP Fibreglass give much better protection against bad weather, although they cost more per m².

GRP fibreglass is extremely durable and can last for around 30 years before needing to be replaced. It’s flexible and can be adapted to suit almost any roofing situation. However, GRP fibreglass isn’t suitable for large roofing projects because of large expansion and contraction rates.

Below are the average m² prices of the most popular roofing materials in the UK to help you plan your garage roof replacement. When you choose a professional roofer, discuss what the best roofing material to use is for your garage.

Cost to install garage materials per m²

Type of roofing Cost per m² Cost per 20m²
Felt £40 £800
EPDM Rubber £45 £900
Tiles £50 £1,000
Slate £60 £1,200
GRP Fibreglass £90 £1,800

Potential water leakage

One of the major problems that a damaged roof can lead to is water leakage. Water leakage is most commonly an issue for flat roofs because standing water can gather on the roof’s surface.

Water can often cause the wooden structure of a garage roof to rot, which will lead to an extra cost being added to your pitched or flat garage roof replacement. Another potential issue is damaged flashings that protect the vulnerable parts of the roof like the chimney. This may add an extra £250 to your new garage roof.

If there’s substantial water leakage occurring, it’s important to temporarily seal it while planning your garage roof repair or replacement. This will prevent any further damage from occurring.

Roof type

Consider the different types of garage roofs available before you agree to the garage roof replacement. Each type of roof has pros and cons, and it will depend on your circumstances which one is right for you.

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What are the different types of garage roofs?

There are two main types of garage roofs to consider when planning a garage roof replacement. Each type comes with various advantages and disadvantages.

The right type of new garage roof for you will depend on:

  • The size of the roof
  • Installation cost
  • Planning permission
  • Your current roof
  • Foundations
  • Installation time

Below, we’ve outlined the pros and cons of both types of roofs and what you should consider when making your choice.

Flat roof

If you’re thinking about a flat garage roof replacement, there are several benefits over choosing a pitched roof. Firstly, they can be installed extremely quickly, normally in only a couple of days as they require fewer materials to construct.

Of course, fewer materials and a faster installation process means less cost – another advantage of flat roofs.

On the other hand, flat roofs can be susceptible to water leakages due to standing water gathering on the roof’s surface, potentially leading to the need for a garage roof repair. Flat roofs generally only last around 15 to 20 years depending on the material used.

Pitched roof

Choosing a pitched roof for a garage roof replacement is favoured by some people as they’re more aesthetically pleasing and can provide extra storage space in the roof void. They’re also more durable and longer lasting.

Most pitched roofs will last at least 50 years, nearly three times as long as flat roofs. This is because the materials used to build pitched roofs are more robust (like conrete, clay or slate tiles). Due to their durability, pitched roofs add more value to your home.

A recent survey by This Is Money found that a new pitched roof can return up to 63% on the cost of your investment. The biggest drawbacks of pitched roofs are the price and the time they take to install.

What building regulations should you consider when replacing a garage roof?

When considering a garage roof replacement be mindful of building regulations that are in place before you begin.

Following a UK-wide set of standards for the design and construction of buildings (including roofs), building regulations help to ensure safety and high standards of construction.

This is the same whether it’s a pitched or flat garage roof replacement.

However, in most cases you will only need to seek building regulations approval if:

  • More than 25% of the total ‘building envelope’ (walls, floors, roofs, windows, doors and roof-lights) is affected; and
  • More than 50% of the roof is affected.

There are some exceptions to this for example if:

  • Structural alterations are carried out
  • There are significant differences in the new roof cover in relation to fire safety
  • The weight of the new roof cover is heavier by 15% or more

Also, you’re unlikely to have to check these building regulations yourself. The roofer replacing the garage roof should ensure that building regulations are adhered to.

The only other time you would need to seek building regulation approval for your garage is if you were converting it into a habitable environment, such as an extra bedroom. Your roofer would need to abide by Part L rules which are designed to increase the energy efficiency of UK homes.

Check with your building control body (BCB) if you’re unsure if approval is needed.

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What do I do if my current garage roof is made from asbestos?

If you discover that asbestos has been used for your garage roof, you’ll need to arrange an asbestos garage roof replacement.

Asbestos was banned in the UK in 1999 due to its harmful effects, such as asbestosis and mesothelioma. So it’s extremely important that you replace it.

The 4-step guide below outlines what to do if your current garage roof contains asbestos.

What do I do if you find asbestos?

1) Leave the garage

If you encounter asbestos in your garage, stop what you’re doing and leave the room immediately. This is to prevent the asbestos from having any potential impacts on your health. Leaving the room as soon you discover the asbestos will help to minimise the risk.

2) Warn your household

Set up a sign outside your garage outlining that you’ve identified asbestos and to stay clear while you resolve the problem. It’s also worth notifying other people in the household, explaining that you’ve found asbestos.

3) Contact an asbestos removal specialist

The safest course of action will most likely be an asbestos garage roof replacement. An asbestos removal specialist will be required to remove the old asbestos garage roof before your roofer can start on the new garage roof. They will be specially trained to safely deal with asbestos removal and disposal.

The cost of asbestos removal varies greatly but is normally somewhere in the region of £300 to £400.

4) Remove the asbestos

The asbestos removal specialist will remove the asbestos garage roof. Once the asbestos is removed and your asbestos garage roof replacement has been complete, your garage will be a safe environment to be in once again.

Garage roof replacement FAQ

What material is best for a garage roof?

If you’re planning a new garage roof, which material to use will be one of the most important decisions to make and will depend on several factors.

However, many professional roofers believe that EPDM rubber is currently the best roofing material available for most garage roof replacement projects. EPDM rubber has several advantages which makes it the perfect choice for most garage roofs.


For a flat garage roof replacement, EPDM rubber is one of the most affordable materials to use. The material costs around £45m² to install, totalling around £1,000 for a complete garage roof replacement.

EPDM rubber is cheaper per square metre than the likes of tiles, slate, lead and fibreglass while still offering many of the same advantages of those materials.

The only roofing material that EPDM rubber is more expensive than is roofing felt, costing more. However, the difference in cost is offset by the benefits that EPDM rubber offers compared to roofing felt, such as durability and longevity.


EPDM rubber is extremely easy to maintain. Unlike roofing felt, the material doesn’t allow the likes of moss and algae to grow, stopping potential damage being caused to your roof. Not only does this offer protection to your home, but it also makes it more aesthetically pleasing.

The average garage roof made from EPDM rubber will last around 20 years or longer before needing to be replaced.


If you’re concerned about the environment, EPDM rubber might be the perfect roofing material for you. The material is made from recycled rubber collected from the likes of used car tyres and window sealants.


EPDM rubber offers excellent waterproofing qualities which can counteract one of the negatives of flat roofs: standing water gathering on the surface.

Think it might be time to get your garage roof replaced? Get more information on our roofing page. Our garage roof replacement cost guide outlines everything you need to know when working out how much a new garage roof could cost.

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