Are fibreglass roofs good? (UK)


Are fibreglass roofs good?

Fibreglass roofs, also known as GRP, can last between 20 and 30 years if they are well maintained. That makes fibreglass an excess choice for your roofing project.

However, fibreglass roofs haven’t been very popular because of a few disadvantages associated with them. There are some fantastic advantages as well, though. Let’s discuss that in detail.

Advantages of Fibreglass Roofs


If you’re planning to install a new roof, then you’ll probably want one that lasts longer than others. If you choose another material for your desktops, you’ll probably end up having to keep replacing them because they aren’t durable enough. GRP or fibreglass is that you can trust for their long life span. It doesn’t crack easily like other materials do. They don’t get damaged by the elements either. In fact, when properly installed, they can be completely waterproof.

Energy Efficiency

The best thing about GRP is its energy efficiency. The material has a high R-value, which will retain heat inside the building better than most other materials. This allows you to save on cooling costs. You can also use less electricity to cool down your home.

Low maintenance

The maintenance required for GRP roofs is minimal. You only need to clean the surface once every year. However, this can be done using a power washer. You won’t have to worry about any kind of repairs.

You’ll always need to keep an eye out for signs of damage to your roof so you can take action before something happens. If you’re repairing fibreglass yourself, you’ll usually end up having an easier time than if you had called someone else in for help.


It doesn’t necessarily need to be used only on houses; it could be used on any type of building. Whatever type of roofing material you need, whether it’s a lightweight one or a complex shape, a GRP roof may be the right choice for you.

Disadvantages of Fibreglass Roofs


They’re expensive. Compared to rubber materials, GRPs cost more.


Fibreglass may not be suitable for every kind of roof. For example, it isn’t ideal for bigger roof sizes. You might find it difficult to work with large sheets of GRP.


Installing a GRP roof requires a lot of skill. It needs to be done correctly otherwise, you risk damaging the structure of your house. You should hire a professional installer to ensure that everything goes smoothly.

Cost of Fibreglass Roofing

Of course, the cost of a GRP roof depends on whether a new roof needs to be built or an old one needs to be altered or renovated.

Obviously, the size of your roof and if you’ll need professional help installing it will affect your budget.

You’ll want to think about whether any structural repairs need to be done to the roof and whether anything needs to be adjusted for the gutters and downpipes. This may also add to the cost.

Nevertheless, the cost may vary between £70-£90 per square metre for a GRP roofing system. However, this price may vary from one place to another. Most roofers charge for reroofs, but some may not. If you decide to install yourself, you’ll save some cash, but you won’t get any warranty from most companies if something goes wrong.


Fibreglass or Glass reinforced plastic roofing is best suited for flat roof systems, but can also be used for pitched roofs with proper consultation with a professional roofer. The lack of seams on fibreglass roofs makes them much less likely to fail and leak water, resulting in water damage, leaking and ponding. If you live in a cold climate, glass reinforced plastics provide excellent insulation properties, reducing heating bills by up to 30%.

Overall, GRP roofs are durable, long-lasting and require little maintenance. They come in different colours and styles. Some are plain, while others can be coloured to match the exterior of your home.  They are also highly resistant to fire and termite attacks. However, they aren’t as flexible as other types of roofing materials. This means that they don’t suit all kinds of buildings.

Fibreglass roofs can be a good choice for your roofing system despite the cons.


Should I Choose a Fibreglass or Felt Roofing System?

It entirely depends on your budget. Felt roofing is much cheaper than fibreglass. It also doesn’t offer great longevity as compared to fibreglass. If money is not an issue, fibreglass could be a better option.

What causes a GRP Roof to Crack?

Thermal expansion can cause GRP roofs to crack. Fibreglass roofs may crack since there are no gaps between the perimeter edges and the board.

How are Leaks Caused in a Fibreglass Roof?

The most apparent reason is cracks on the surface of the roof. Improper installation is generally the reason for cracks and eventually leaks.