One seamless skin, no joins to fail
This was a large garage roof — the sort of span where a felt roof gives you a lot of joins, and every join is somewhere a leak can start.
The old covering came off and a fresh OSB deck went down first, because there's no point laying a good roof over a soft one. The GRP then goes on as one continuous, seamless layer, dressed into the edge trims all the way round.
Nothing to lift in the wind, nothing to split in the frost. We're GRP certified, and this roof — like every fibreglass roof we install — comes with a 25-year guarantee.