Fibreglass roofing is often known as GRP roofing and this is because it is made of Glass Reinforced Plastic. The process involves mixing polyester resin with tiny glass fibres to create a composite. The glass fibres effectively reinforce the plastic resin making fibreglass much tougher.
For roofing, the fibreglass is cut into uniform sheets that can easily be laid. It is a moldable product, so it can take the form of the shape that it is laid on. This makes it a versatile option for different shaped roofs.
It is possible to lay a GRP roof yourself, with the use of a fibreglass roof kit. But, while it is possible to DIY your fibreglass roof, that doesn't necessarily mean that it's the best idea. Calling in a professional to lay the roof for you is often the best idea if you want it to last as long as possible. It is also possible that you may inadvertently void the warranty on the fibreglass roo kit if you lay it yourself incorrectly.
Fibreglass roof kits contain everything that is needed to lay a fibreglass roof. Some fibreglass roof kits also include the tools that will be needed, and these are useful for people who are going to be completing the project themselves. Other kits only contain the fibreglass roofing materials and these are perfect for roofing contractors or people who already own all of the tools.
In your fibreglass roof kit, you will usually find:
Each fibreglass roof kit varies, however, so it is worth doing some research first to find the one that is best suited to your GRP roof.
If your roof kit does contain tools as well as materials, this will usually include:
Installing GRP roofing systems is a multi-step process that will require specialist fibreglass roofing products. In brief, a layer of catalysed resin is applied first, followed by a fibreglass mat, then another layer of catalysed resin and, finally, a top coat.
The first thing that should be done is to check that the current decking is suitable for fibreglass roofing. If the decking is in good condition and is, for example, something sturdy such as sterling board or plywood, then the fibreglass roofing can often be laid directly on top.
If it isn't or if the building is still under construction, then it will need to be replaced before the GRP roof can be installed. Onboarding with OSB boards, or something similar, can help to ensure that the decking below is sound and waterproof.
Careful consideration of the weather conditions is also important before going ahead with the GRP roofing. A GRP roof cannot be installed in all weather conditions. The conditions will need to be both dry and mild. If it is too cold outside, then the resin will not cure.
There is a wide range of GRP roof trims available, all of which are suited for different purposes. For example, a drip trim helps to direct water into the gutter, a raised edge trim stops water from dripping over the edges of the roof, and a wall fillet trim lays flush against an adjacent wall and creates a waterproof seal.
GRP roof trims are usually attached using clout nails with sealant applied to any joints. Flat roof outlets are often also installed to further help with drainage.
The flexible roofing resin should be carefully mixed with the catalyst in a mixing bucket. The resin should then be applied with a roller to the decking and the GRP trim.
The GRP trims should then have GRP bandages applied with another layer of resin on top.
Once the decking is covered with resin and the trims bandaged, the fibreglass matting can be installed. Then make sure that the area is clean from any dirt or debris.
Make sure that the matting is measured and cut beforehand. Roll each length of matting onto the roof, making sure that it overlaps so that the roof is completely covered. It should be laid on top of the bandaged GRP trims.
The mats usually have one straight edge and one weathered edge which can help you to create a smooth and attractive appearance (each feathered edge should meet a straight edge).
Each section of the fibreglass mat should be covered with another layer of resin. This can be quite an intricate process and it is important that no weight be placed on the matting before it has finished curing. So planning where to begin and where to end the job is important.
The top coat is the final step in installing a fibreglass flat roof. It can be installed as soon as the laminate is no longer sticky and if it is applied within 12 hours, there is no need to sand the laminate down first. The top coat will also need to be mixed with the catalyst and it is usually applied with a roller.
There is a range of options when it comes to fibreglass roof topcoats. It comes in a variety of colours, so you don't have to stick with just grey or dark grey (but these options are popular for a reason).
You can also choose between a fire retardant topcoat and a standard roofing topcoat. A fire retardant topcoat is a good option if you are going to be installing flat roofs on an outbuilding that adjoins your house.
We've touched a little bit on some of the benefits of a GRP roof, but let's take a look in a little more detail. Fibreglass roofing isn't for everyone and it isn't for every project, but it can be far and away the best option for many.
GRP flat roofs have an excellent reputation for durability. If they are installed properly, ideally by a roofing professional, you can expect them to last upwards of 25 years.
GRP roofing is crack resistant even from impacts, fire retardant (depending on the topcoat), waterproof, and can cope with footfall (making it suitable for a floored flat roof). They are completely seamless which makes them very resistant to damage.
GRP roofing is suitable for a range of weather conditions. It is almost completely watertight, especially when edge trims have been included, so will hold up under very wet weather. It is also highly resistant to UV damage so will do well in hot weather as well.
GRP roofing can be applied to marine-going vessels, using Lloyd's approved resin, so you can be sure that it is as watertight as you are going to find.
A GRP flat roof is relatively easy to repair. A big benefit is that it can be patch-repaired using a patch repair kit without the patch being noticeable and without it reducing the lifespan of the GRP flat roof.
One of the biggest draws of a GRP flat roof is its attractiveness. When installed correctly, this type of flat roofing gives a seamless, clean, and modern appearance. It can also come in a variety of colours so it can be tailored to your own tastes.
Because of the nature of the materials used to create a fibreglass roof, they can be used even in situations where the roof shape is unusual or is pitched. This is because they are able to mould with the roof shape much more easily than something that is already hard before laying.
The materials are also very lightweight so can be used for roofs that would be unable to bear a heavier flat roof surface.
Even with all the benefits of a fibreglass roof, there are some things that you may need to consider before getting one installed.
Per square metre, GRP fibreglass flat roofing is a more expensive option than some of the others available, such as a rubber roof or a felt roof.
The increased cost is partly because a GRP roofing system uses specialist roofing tools and expensive materials, and partly because it is usually recommended that the fibreglass roofing kits be installed y a roofing professional.
With that being said, the many benefits that can arise from GRP flat roofing can make the extra cost worthwhile. And, because it is durable and easy to repair if it is necessary, it may end up costing less over time than an option that has a lower initial cost.
This has been touched on but installing GRP roofing and making sure it is fitted correctly is much more difficult to achieve DIY than other roof options such as felt or EPDM. The roofing kits often do contain all the materials you will need but making sure that they are applied correctly is a skilled task that will often require a professional with a wealth of experience.
Installing a new roof, or replacing an existing roofing system for a flat roof, can require some thought to choose the right option. Installing a GRP roof is perfect if your priorities are durability, longevity, and attractiveness. Get in touch with us today to find the right fibreglass roof system for you, and we will ensure that it is properly and professionally installed so that it lasts for many years to come.