top of page


A GRP flat roof, or fibreglass roof as it’s also known, is one of the most popular flat roofing solutions in the UK. GRP stands for Glass Reinforced Polyester, a composite material formed by strengthening plastic with fine fibres made of glass.


This single ply laminate has been used as a reliable means of covering and waterproofing roofs for over 60 years, although it's popularity has soared in recent years thanks to new systems such as Cromar. As well as commercial and domestic buildings, GRP has been used on a wide array of other applications, from boats and lorries to water tanks and ponds.



The installation of a GRP roofing system is highly regarded for its safety, while the finished product it produces is recognised as having a lifespan that easily betters that of a felt roof.   


GRP flat roofs begin with a layer of catalysed resin being applied to a roof decking. A layer of fibreglass mating is then laid on top followed by another layer of catalysed resin to complete the system. Once cured, a fire retardant top coat resin is then applied to completely weatherproof the roof and give it a more attractive finish.


Specially made edge trims and drip trims are fitted to the edges of the roof and abutments before any GRP is laid down


If sensibly looked after, there is no reason a GRP flat roof cannot last for at least 30 years without any measurable deterioration.



The overall cost of any GRP roofing system will depend on whether a new roof is being constructed or an existing roof is being replaced. The latter will, of course, be cheaper. You can reach out to us to get a free, no obligation quote by clicking here and filling in your details.​


Given the greatly superior durability of GRP roofing to felt systems, you might think that a GRP flat roof would cost a great deal more. This is not the case.


Although GRP is pricier than felt or EPDM rubber roofing systems, when you factor in this impressive longevity, along with the lack of maintenance needed, resistance to all weather and attractive laminated finish, fibreglass roofs can be worth every penny.



Repairs are not something you’d associate with a GRP flat roof. We would make sure that the project is carried out on suitable decking with properly installed trims and flashing, so your GRP roofing system will provide little cause for concern.


Although impact resistant, should your fibreglass roof somehow develop a split or hole, there is nothing to stop another round of GRP being laid on top as long as the roof is still structurally sound.


Fibreglass roofs are unaffected by UV but fading can occur over the years. This will only affect the aesthetical quality of the roof, nothing internally. Should you want, any loss of colour can be combated by applying another layer of top coat to restore your GRP roof to its original glory.

bottom of page