GRP Roof Leaking

31 Mar 2006
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United Kingdom

I'm having a bit of a nightmare. Over the joists of my garage I laid OSB T&G, wetted it out then laid 600g CSM followed by more resin then a topcoat. It's only been down about 2 weeks but now there is heavy rain there are drips coming through the joins of the OSB board in about 3 places. I went up and inspected the roof and there are a few areas where the topcoat is very thin and you can clearly see the fibres of the CSM. Are these thin patches of topcoat enough to cause the roof to leak?

Thx Rich
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Top coat it again.

Yes it will leak through if the top coat is a bit thin and the water may be lying in places too.
Okay thanks. I've ordered another load of topcoat and about 40 x 60 grit sanding pads :(. I guess the areas short on top coat are also low lying so the water is pooling in there making it worse.
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Hard graft fibre glassing a large area and you should not see any fibre strands prior to top coating never mind after!

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