Fibreglass roofing guide - introduction
We are happy to give advice on the basis of our experience; but we accept no liability for that advice and you should rely upon your contractor or other professional.
You can also download this guide (PDF)
Safe working practices
It is always the contractor's responsibility to ensure safe working practices for themselves and their employees and consider the risks to other members of the public that may be nearby at the time.
Advice when laying a GRP roof during winter months
Always check the local weather forecast to ensure conditions will be acceptable.
New Premium Zer0° - the only cold weather roofing resin and topcoat – a resin and topcoat that you can use throughout winter even when it’s bitterly cold! Premium Zer0° can be used below 10°C. In fact it will cure at temperatures well below 10° and many of our customers are successfully laying roofs this winter down to freezing point.
- During the winter, avoid topcoating a roof after 2pm unless it is a clear bright day and not too cold. The heat from the sun contributes a great deal towards the curing of the laminate during colder months. After the sun has set, it is unlikely that the topcoat will cure over night. If left uncured, the topcoat may cure with debris and leaves stuck to the surface, or with an undesirable finish if it rains.
- Ensure that the surface temperature of the boards is checked before laying the resin or topcoat.
- Ensure that the resin is warmed before use if the ambient temperature is below 10ºC. This can be achieved by leaving it in a warm room the night before a job.
- Do not use resin or top coat in temperatures below 5ºC.
- If it begins to rain, stop immediately and cover the roof with a visqueen sheet, keeping the roof as sheltered as possible, the decking will need to be completely dry before continuing.
- If you are unable to laminate over a prepared deck before it will rain, then coat the decking with catalysed resin and cover any exposed edges. This will seal the deck and prevent moisture uptake until the laminate can be applied.
- Always ensure the deck or substrate to be laid onto is completely dry before laying the laminate. Sweep off any excess water and mop up the excess with dry cloths before allowing the roof to dry naturally.
- Do not start to lay a roof if a period of rain is forecast.
Advice when using GRP during summer months
Always check the local weather forecast to ensure conditions will be acceptable.
- Do not use resin or top coat in temperatures above 35 degrees C.
- Always mix smaller batches of resin then you normally would to give adequate time to apply it before it starts to catalyse.
- Always use LPT catalyst in hotter weather if the resin starts to cure too quickly.
- Always apply the laminate in the shortest runs possible across a roof. The shorter the length of laminate, the less likely it is that the resin will catalyse before it can be consolidated into the CSM.
- Use a temperature sensor to measure the surface temperature of the laminate before applying the topcoat. If topcoat is applied to surfaces at very high temperatures, the wax component of the topcoat will melt and the topcoat will remain tacky to the touch, this will usually mean that any loose debris will stick to the roof and the colour of the topcoat will also be impaired.
- If possible, topcoat the roof out of direct sunlight or wait until later in the day before applying it, it may mean that the roof will take you longer to complete but it will save you time spent returning to the roof to re-topcoat it at a later date.
Cleaning Tools and Equipment
Buckets can be re-used for many jobs. When each mix is finished with, coat the inside of the bucket. When the resin has cured after approximately 30 minutes it can be peeled out, leaving the bucket like new and ready for the next job.
Paintbrushes can be dropped into a re-sealable container of acetone and left for the next job. Use only paintbrushes that have unpainted or uncoated handles, as the coatings will come off and contaminate the resin.
Polyester rollers have sleeves that are removable. It is very time consuming to clean the roller sleeves, so unscrew the nut with pliers and drop the used sleeve into the bucket of used resin.
Either use disposable latex gloves when handling catalysts and resins or clean hands with an appropriate hand cleaner. Do not clean hands with acetone.
Painters wipes are also a useful addition to your toolkit. As well as cleaning hands they are good for removing resin from windows and fascias.