Flat Roof Repair
Portsmouth

GRP Flat Roofing in Portsmouth

Portsmouth has a high density of terraced housing, with a large number of properties featuring rear extensions, outbuildings and bay window roofs covered in traditional felt. Felt flat roofs have a lifespan of around 10–15 years and fail most commonly at the lap joints — the overlapping seams between felt sheets. We replace failing felt systems across the PO1–PO6 postcodes with GRP fibreglass, which has no joints and carries a 20-year manufacturer guarantee.

Our GRP flat roof process in Portsmouth starts with a full strip of the existing felt back to the deck boards. We inspect the deck for rot, movement or damage and replace any boards that are not in sound condition before laying the new system. Aluminium edge trims are fitted and fixed around the perimeter, a primer coat is applied to the full deck, and primer bandage is bedded into all joints and junctions between the deck and any upstands or walls. The GRP topcoat is applied across the whole surface in a single continuous pour — no laps, no seams, no lap joint failure. A coloured gelcoat finish is applied to complete the installation.

Where the existing deck is in good condition and only a localised area is leaking, we can carry out targeted GRP repairs rather than a full replacement. We will always assess the roof and give an honest recommendation on whether repair or full replacement is the better value option for your property. All installations include a written workmanship guarantee alongside the manufacturer's 20-year product guarantee.