Fibrelast

How many expansion joints are needed for a GRP roof?

Asked by ellaweston · January 2026

We have a roof that's 54 square metres and I know from your Fibrelast guide that we need to use expansion joints. Can you tell me how many we'll need for a roof of this size?

✓ Allbase answer

Allbase team

The number of expansion joints needed on a GRP fibreglass roof depends on a number of factors, such as whether anything breaks up the space, windows for example. As a general rule of thumb, allow one expansion joint per 50 square metres.

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