Is your fibreglass roof looking worn out or leaking? Before you replace a fibreglass flat roof, consider whether you can repair it instead, saving money while prolonging the life of your existing roof. Many homeowners and DIYers find themselves in this situation, wondering if they can fix it themselves. The good news is, that with the right knowledge and roof repair kit, you can repair your fibreglass roof instead of shelling out for a roof replacement. This article will take you through the process and help you decide if a fibreglass roof repair is possible.
When to Repair a Fibreglass Roof Instead of Replacing It
Knowing when to repair your fibreglass flat roof versus replacing it when you experience common fibreglass roofing problems will save you time and money. GRP fibreglass roofs are durable but like all materials, they can develop leaks or damage over time.
If the fibreglass roof leaks are localised and haven’t been persistent enough to cause internal structural damage, a repair kit is usually the way to ensure the roof remains waterproof. Look for minor punctures or cracks that haven’t spread too far. If multiple leaks have been there for a while and have caused underlying damage, a full replacement might be needed.
A fibreglass roof repair kit is also good when the damage is recent and hasn’t affected the sub-structures of your fibreglass roof. Quick action is key here to prevent further fibreglass roof problems. If your roof is generally in good condition apart from a few trouble spots, repairing those areas will restore its integrity without the need for a full rebuild.
Repairs are more cost-effective and quicker, so they’re a good option for minor issues. The decision comes down to the extent of the damage and the condition of the fibreglass. In short, assess the damage and impact before you repair or replace.
Do I Need Planning Permission to Repair My Roof?
Before you climb that ladder, it’s good to know the rules around flat roof repairs. In most cases, repairing fibreglass roofs does not require planning permission as it’s permitted development, but this can vary depending on location and circumstances.
For listed buildings or properties in conservation areas, you may need permission before making any changes. Always check with your local planning authority to see if there are any restrictions on your property.
In most cases, repairs that comprise less than 25% of your fibreglass roof won’t need planning permission, while flat roof repairs covering over 25% of the roof or that require structural changes may need permission.
How to Fix Your Fibreglass Roof
Find the Leak
The first step in fibreglass roof repair is to find where the leak or water ingress is coming from. Leaks in flat roofs usually come from punctures in the roofing membrane. Inspect your roof carefully, and look for any obvious holes or cracks. If the leak is new and there hasn’t been much rain, fibreglass roof problems are likely repairable with a roof repair kit.
Make sure the roof surface is completely dry before you start any work, damp conditions will hinder the installation process. Use a plastic cover over the repair area during rain to keep it dry. Don’t try to bond resin to a wet fibreglass surface as this will affect adhesion.
By finding and fixing the source of fibreglass roof problems, you can contain the damage and complete your fibreglass roof repair without any hassle.
Clear the Area of Loose Debris
Before you start the repair, clear the area thoroughly. Remove any loose debris, dirt or damaged roofing material. This will give you a clean surface for the repair materials to bond to. Use sandpaper to smooth out the area, to create a flat surface for the new layer.
Safety is important at this stage. Wear a dust mask to prevent inhalation, safety goggles to protect your eyes, and gloves to prevent cuts from sharp debris. If the roof was installed before 1999, be careful of asbestos.
Clearing the area sets the stage for a good repair, so the new materials bond properly and the roof remains waterproof.
Apply a Resin Primer (Optional)
Primers are not always necessary but can make the repair more durable and increase the life expectancy of fibreglass roofs. A resin primer helps the new fibreglass laminate bond better to the existing surface. Apply a thin coat over the repair area, making sure the surface is covered evenly.
Prepare a Region of Chopped Strand Mat (CSM)
Cutting and sizing your chopped strand mat, also called glass fibre matting, is important for a good fibreglass flat roof repair. Use a 600-gram chopped strand mat for strength. 450-gram is also available. Follow the manufacturer’s instructions and cut it to 10-20% beyond the damaged area so it covers the perimeter edges of the affected area.
Be careful when handling CSM. Use a Stanley knife with blade-resistant gloves to protect your hands. This will give you precision in your cuts and safety while working.
Apply Resin to the CSM
Mix your polyester resin with a catalyst in a clean container. Use a short pile roller or paintbrush to apply the catalysed resin to the CSM on the affected area. Place a second smaller piece of CSM on top for extra reinforcement and saturate it with resin.
Use a paddle roller to remove air bubbles and excess resin, for a smooth, even application. This should be done in dry weather, as moisture will hinder the curing process.
When installed properly, this process will give you a watertight seal and reinforce the repair of fibreglass roofs.
Allow It to Cure
Once applied, let the laminate cure. This will allow the resin to harden and form a water-resistant barrier. Typically, you should let freshly repaired GRP fibreglass roofs cure for 12 hours in winter and 6 hours in summer, but this can vary depending on conditions.
Make sure the repair is kept dry during this time. Cover it if there’s a chance of rain to protect the curing process to ensure an effective repair.
Apply a Resin Topcoat
After curing, it’s time to prepare your GRP roofing topcoat. Mix it with a catalyst and be careful not to create bubbles. This top coat will seal and protect your repair if installed correctly, making it waterproof and abrasion-resistant. You can use dye to make your GRP roofing topcoat the same colour as your roof.
Apply the topcoat (or flowcoat) evenly over the laminated area. Use a polyester laminating roller to spread it, don’t let it pool or over-apply it. Too little top coat resin will cause poor installation and too much will be brittle. Finding the balance is the key to a good topcoat. This final layer will protect from the elements.
Allow it to Cure
Like the laminate, the topcoat needs time to cure. Allow 12 hours in winter and 6 hours in summer for it to fully harden. Again, cover the area from rain during this time.
This final curing will solidify the repair, for durability and weather wear.
Patience will pay off, it will all be worth the effort and care you put into the repair.
Why Choose a Resin Library Fibreglass Repair Kit?
A Resin Library repair kit is a complete solution for fibreglass repairs on flat roofs. They include everything you need to get your GRP roof repaired and are designed for ease of use for DIY users and professionals.
The roof repair kit is designed to effectively repair small holes, cracks, and other damage, providing a protective coat and waterproofing roof surfaces. They come with instructions for those new to fibreglass work. With a Resin Library kit, you can be sure you are using the right materials for the job.
Conclusion
Repairing a fibreglass roof doesn’t have to be difficult. With planning and the right materials, you can extend the life of your roof without replacing it.
Each step of the process is designed to give you a durable and effective repair. From prep to the topcoat, attention to detail is important when repairing GRP fibreglass roofs. If you want to learn more or need an excellent flat roofing system for your next project, check out Resin Library today.
