GRP or Rubber Roofing: Which is Better?

With the two roofs systems of GRP and rubber there are a lot of pro’s and con’s regarding the two systems as to which one is better?

GRP is more expensive due to the cost of the material list, with the items involved with GRP build up. Of the two materials GRP is more robust and can take a lot more punishment to the deck area’s than rubber roofing.

However, when you come to the upstand details with GRP they are not as strong as rubber, as the trims at upstand junctions are hollow at the fillet lines (even with 600g mat reinforcement). GRP is a lot more rigid as a system, whereas rubber is highly flexible and with a fleece back system such as Firestone1 and Flexr2, these are of higher spec than most on the market.

With EPDM systems there are quite a few weak areas such as the lap joints and external/ internal corners, as these are glued or bonded and sometimes, due to the complex detailing, are difficult to seal and some systems have now introduced a rubber pitch pocket to achieve these awkward areas.

Modern Fibreglass Roofing systems such as poly roof can cope with complex detailing with 225g CSM matting and can cope without trim edges and are self-terminating. Systems such as Ultraflex GRP3 are highly flexible and can cope with irregular shapes. GRP are great for roof gardens being as all of the joints are seamless, as some of the rubber roof systems are not anti-root and cannot be used on green and brown roof garden projects.

As the rubber systems have emerged, better systems have come to the market such as Resitrix, this system is heat welded and all the lap joints as with an RBM system show a ‘Bleed line’ at the lap junctions. With rubber being highly flexible and GRP being highly rigid the question as to which is better cannot be answered. 

Both when fitted correctly are visually appealing, the cost of GRP being slightly higher and coming with a higher guarantee overall, but rubber is easily installed and cheaper at the low end of the market. We think both systems have stood the test of time and will keep on being produced and installed for years to come.

If you would like any more information on how GRP roofing compares with Rubber roofing, please get in touch with Guaranteed GRP or call us now on 0208 702 8063 one of our GRP specialists will be happy to help.

If you would like to learn more about GRP Roofing our blog is full of information.