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Reasons for a Leaking Fibreglass Flat Roof

If you have noticed you have a leak in your GRP/Fibreglass Flat roof the best thing you can do is to contact a roofing contractor to come and conduct a roof survey. This will help identify the cause of your leak.

Common reasons for leaking fibreglass roofs include:


This can be caused by the expansion and contraction of your roof when the weather changes form hot to cold. Your fibreglass roof should be built with some allowances for the movement in your roof due to temperature changes. However in some cases the roofer who carried out the installation may not have allowed for these temperature changes. This is normally due to poor planning when fitting the decking boards. This can result in cracks appearing and these are likely to result in leaks.

Pin Holes

A fibreglass roof can sometimes develop extremely small pinholes on the surface. The reason for this is insufficient resin being used during the installation process. This problem can deteriorate over time and lead to leaks.

Problems with Flashing

Sometimes the leak can be coming from the flashing especially the joint where the roof covering meets your wall. If there are cracks in the flashing or it is pulling away from the wall it will need replacing as it is a likely source of your fibreglass roofing leak as this is a place where water can penetrate your roof.

To get the most out of your fibreglass roofing and to prevent leaks it is important your roof receives regular maintenance. And to carry out any necessary repairs. If you are in the Woking or Guildford area and need any fibreglass flat roofing repairs or maintenance please get in touch today or call us on 01483 475141.