Frequently Asked Questions

Where can a GRP waterproofing system be used?

We predominantly use fibreglass for flat roofing projects either replacing a bitumen felt roof or installing a flat roof to a new build property. We also apply the system to Valley gutters, box gutters bay windows in fact there are very few areas where a fibreglass system cannot be used. We have carried out 1000's of m2 of GRP to commercial buildings.

How long will it last?

The oldest glassfibre laminates still in use were made in the late 1940's and 1950's. The oldest boats made from glassfibre are now over 60 years' old and no deterioration in the glassfibre can be found. We believe that an appropriately constructed glassfibre moulding will last in excess of 60 years. Where the glassfibre has been kept immersed in water, as in a boat hull, or exposed continuously to the elements, as in a boat deck, there is no evidence of deterioration of the laminate in either application.

What is Glass reinforced polyester?

The glass is normally a mat of chopped glass fibres which is used to reinforce resin to make a structural "composite". This can be designed to suit almost any application.

What is a polyester resin?

There are a number of resins, which may be used to bind the reinforcing glass together - for example, epoxies, polyurethanes, phenolics but polyesters are the most popular. This is because their properties can be easily modified, thus being easy to use at room temperature, and they are generally lower in cost than the alternative.

Are polyesters hazardous?

YES. They are classed as CAT 3.3 which means of relatively low hazard but that they need to be treated with care. Polyester resins are dissolved in styrene, which is the source of the hazard. Styrene is inflammable (Flash Point 32 deg. C) and is classed as an irritant. Styrene has no known health effects associated with it but it has a very strong smell, which most people can detect, at very low levels. You should always use polyester resins in a well-ventilated area. Ventilation doesn't get better than on a roof!

Can I walk on a GRP roof without the risk of damaging it?

Yes GRP is very strong and durable. The fibreglass laminate is fully bonded to an 18mm timber decking board. It is suitable for flat roofing projects and is also recommended for balconies and walkways as there are very few other materials to match its performance. It will give a structural coating that can be left exposed, tiled over, paved over or even concreted over if required.

Can a GRP system be used in areas where there are complicated roof details?

Yes. As GRP or fibreglass is a cold liquid applied system wet laid in situ it is particularly suited to complicated detail where other systems would fail because of joints and laps. Sealing around soil pipes and into gullies can be easily carried out without the need for specially made aprons and seals.

Will extremes of weather affect my roof?

No, because GRP is a thermoset and not a thermoplastic it will not soften or distort in heat. The topcoat will protect the laminate from Ultra violet radiation. Even without being top coated the laminate would have a life span of at least 20 years before starting to show the effects of UV deterioration. Frost and ice will not shorten the life of a GRP roof as Fibreglass can withstand temperatures far lower than we have ever experienced in the uk.

Will ponding water affect my roof?

No. Because a fiberglass roof is seamless there is no risk of water ingress into the structure of the roof there are no laps or joints where water might freeze to force a joint apart. Many existing flat roofs have stood for 20 to 40 years, over a period as long as that it is inevitable that the timber joists will 'sag' or bow slightly. This will cause a roof to pond or hold an amount of water. Ponding water will not affect the performance of the roof.

How long will it take to install a fibreglass seamless roof

As an example a typical single garage roof can be fully stripped, re-boarded and installed with a GRP waterproofing membrane within a day. There for there is very little disturbance.