Phone Number: 01264 551 007

When Should I Choose GRP Fibreglass Roofing

  • Posted by:
  • Admin
  • Tags:
  • Roof, Fiberglass, Material, Resin, Seams
  • Posted date:
  • 06-02-2023
When Should I Choose GRP Fibreglass Roofing

Have you asked: When should I choose GRP fibreglass roofing? Our company provides GRP fibreglass roofing installations throughout Andover, Basingstoke and Winchester. We look at the many reasons to consider GRP Fibreglass for your flat roof.

What is GRP?

GRP stands for the phrase, glass-reinforced plastic, and it is a material manufactured out of a polyester resin. This material is then reinforced through the use of chopped strand mat glass fibres in order to form the GRP laminate. GRP has become such a popular choice in the modern age because not only is the composite material extremely strong, but it is also relatively light.

The material was originally invented in the 1930s to be used on boats and other water-related containers, but it soon found an important place in the construction industry. More specifically, GRP is very commonly used in roofing. The GRP we use today is much stronger than the original incarnation being used in the thirties and forties, but its core properties are still exactly the same. GRP is highly durable, very flexible, waterproof, lightweight, and well-reinforced.

Why Choose A GRP Flat Roof?


When it comes to waterproofing performance, GRP fibreglass is absolutely unmatched across all roofing materials. Once the GRP has been installed correctly, the material creates a completely impassable barrier that will not allow any liquids through. This means that not only is the material completely waterproof, but it is also weatherproof. 

No matter how rainy, windy, snowy, or icy it may be outside, your GRP flat roof will still be in excellent shape, protecting your property. The only way that the GRP material can become damaged is by impact, for example, a large branch falling onto the roofing. But even this is very easily fixed.

Zero seams mean no worries

The majority of flat roofing materials, such as felt and even modern membrane systems, are highly flawed due to their installation being reliant on welded or glued seams. For any flat roof, these areas are clear weak points which are likely to cause issues. One of the excellent reasons to invest in a GPR fibreglass roof is that they have no joints or seams. The whole roof is one completely flat and smooth surface which cannot be penetrated even when high pressure has been applied.

Easily Repaired

Under the normal usage and circumstances of maintaining a GRP fibreglass roof, there should never really be a reason for it to be repaired. However, in the unfortunate scenario where the GRP fibreglass roof does become damaged, for example, if the material is punctured due to an impact, then the process of having the roofing material repaired is quite simple. 

All that needs to be done is first cut out the area of the roof that has become damaged. Next, the area will need to be sanded down and then, finally, replaced with a GRP patching kit. This replacement material will bond directly onto the original roofing with absolutely zero detriments to the performance of the roof.

Strength of the Roof

When it comes to the strength of a GRP fibreglass roof, there are several different options available. 450g, 600g, and 900g fibreglass layers are available depending on the amount of footfall this area will be receiving. If you think that you or others will be walking on the flat roof commonly, then the options you will be wanting are the 600g or 900g choices. 

There is always the other option of using the 450g equivalent and then just doubling up and using twice the amount of layers. Once the material has been properly installed, the fibreglass in the roof will create a huge amount of strength, so feel free to walk all over the material as you please.

Minimal maintenance

The best roofing options available are the ones that just do exactly what you are asking of the material and don't require you to be constantly worrying and taking care of them. This is another one of the reasons why GRP fibreglass is the best for flat roofing. These roofs require no maintenance at all unless they somehow become damaged, need cleaning, or have slightly shifted due to a rare occurrence such as an earthquake.

The majority of people who have GRP fibreglass roofs installed never even think about maintenance and never have a reason ever to touch their roofs. They can just forget about it and let the fantastic material do all the work.

Ideal for rooftop gardens

As mentioned earlier, GRP fibreglass is completely impenetrable. This makes the flat roofing material the perfect choice if you are thinking of having a rooftop garden. If you are planning to create a garden set-up on your roof, then it is recommended that have some drainage points installed, but apart from this, GRP fibreglass is an ideal fit for anyone considering a rooftop garden. The strength of the material also means it can easily hold the weight of all the additional soil, greenery, pots, and even tables and chairs.

Long Lifespan

Remarkably, GRP fibreglass roofs have a lifespan of well over thirty years. As well as this, the majority of branded fibreglass products you can purchase will come with a minimum of a twenty-five-year guarantee. Some will even stretch to fifty years. That is an extremely long time. 

One of the unique properties that GRP holds is that it is completely inert. The material simply does exactly what you would want from a roofing material, and it will not degrade over time. This is the reason why the long-term cost of purchasing and having a GRP fibreglass roof installed is so low.

Outlasting Other Materials

When you are looking at all the options available for your roofing, you might be tempted to go with one of the flat roofing system alternatives, such as asphalt, resin, or felt. These options may save you a couple of hundred pounds initially, but overall, you are going to be paying a much higher amount. 

These cheaper materials degrade at an alarming rate, and it won't be long before they need to be fixed or perhaps even entirely replaced. GRP will outlast felt and asphalt roofs by more than five times. This makes GRP fibreglass roofs the ultimate choice if you are looking to save money in the long term.

Help The Environment

Another excellent reason to invest in a GRP fibreglass roof is that they pose zero risk to the environment during the installation process. This means that the equipment used does not emit any harmful fumes or toxins. 

As well as this, GRP is completely inert, meaning that the material does not begin to break down or rot as time goes on. This is good for the environment as it means that no nasty chemicals can seep into the water supply.

Perfect for Period Homes

GRP fibreglass is a perfect fit for anyone currently living in a period home. This includes listed buildings! Studies have shown that local planning authorities approve eight out of ten applications for having old felt or resin systems replaced with new modern GRP flat roofing. If you reside within a listed building that currently has a leaking flat roof, then you should consider having it replaced with a material which is not only better value for money but overall much higher performing.

How Much Does a Fibreglass Roof Cost?

On average, you should be expecting to pay somewhere between £70 to £90 per square metre for a GRP fibreglass roof. However, this price can either rise or lower depending on where you are based in the country. You will also find that the majority of roofing companies will include the costs of reboarding in their fee. As with any home construction work, DIY will always be cheaper, but this can very easily lead to an incorrect installation and your warranty becoming voided with some manufacturers.

Are you looking for a GRP flat roof specialist in Andover, Basingstoke or Winchester? Our company provides GRP fibreglass roofing installations throughout Andover, Basingstoke and Winchester.

If you find yourself in need of a replacement flat roof, don't hesitate to contact Flat Roofers Basingstoke today! We have staff on hand to answer any questions you might have.