Glass Fibre Roofing FAQ's
Q: Once flow coat has been used, is it possible to bond to the wax-modified resin if changes or repairs are needed to the structure?
A: Yes it is possible, you need to clean the area thoroughly (preferably using Acetone) then sand back the surface before carrying out your repair.
Q: We have a flat glass fibre roof with a 3" gutter running from the middle sloping slightly to both ends of the roof where there are drainholes. When it rains heavily, the rainwater pools within the gutter because of a slight dip. This is causing a leak though the roof. Can you suggest a material which i could use to fill the dip and stop the water from pooling and so hopefully it will drain away more quickly. Unfortunately the previous owners have tried to apply a waterseal paste to the gutter, but this has not worked.
A: You will need somebody to look at this problem before commenting... If the water has already come through the roof you could have problems that cannot be seen from the outside. Layers of Glass Fibre can be laid into the dip to bring the area to the same level, but you may be covering up a problem. Please call our offices if you would like to discuss the problem in further detail.
Q: Can I use the CYB roofing system on surfaces such as concrete and asphalt?
A: Care needs to be taken when laminating onto these surfaces, you will need to use a primer on new concrete & asphalt. CYB have primers for these situations.
Q: Can I laminate over bitumen?
A: Bitumen will inhibit the cure of GRP. Again, you will need to use a primer coat first.
Q: Why should I use OSB Sterling boarding rather than plywood?
A: OSB3 Sterling board is the ideal board for GRP roofing (a recommended choice is 18mm, 8 x 2 tongue and groove). GRP will adhere better to OSB3 and if you are using Tongue and Groove there is no need to tape the joints as resin will fall into the gap and adhere the boards together well. As T & G lock together it transfers all expansion to the perimeter edge therefore there is no need to leave expansion gaps between the boards. The 8 x 2 sheets are perfect for roofing as they are easily carried.
Q: Can I use plywood?
A: Yes you can but we recommend that you use a quality grade – WBP 18mm – you will need to sand the surface before you laminate as bonding to plywood can sometimes be difficult. You will need to consider expansion joints when using anything other than T & G.
Q: How do I bond the pre-formed trims to the boards?
A: The pre-formed trims can be nailed to the boards or you can use a Polyurethane sealant such at CT1. Do not use a silicone sealant as silicone will react with GRP.
Q: Once flow coat has been used, is it possible to bond to the surface if changes or repairs are needed to the structure?
A: Yes it is possible, you need to clean the area thoroughly (preferably using Acetone) then sand back the surface before carrying out your repair.
Q: What colours are available?
A: All RAL or BS colours are available to order. At CYB we have a large stock of all standard roofing colours (Mid Grey, Dark Grey and Black) as well as British Racing Green and White.
Q: It’s a really hot day and my resin keeps going off too quickly – do I add even less catalyst?
A: It is important that you do not use less than 1% catalyst (10ml per kg of Resin) as it will not cure efficiently. Try mixing less quantity of Resin at a time. Resin will cure quicker in the bucket than on the roof as it will exotherm in mass. In very hot weather try to make a temporary shade or work earlier or later in the day to avoid direct sunlight.
Q: It’s a really cold day and my resin is taking ages to go hard. What do I do?
A: You can add up to 4% catalyst to the resin (40ml per kg) but do not use anymore as it will have the same effect as not using enough “it will not cure”! Try leaving the resin in the bucket for a few minutes before using so that it creates heat. If possible, use heaters on the laminated area to speed up the curing process.
Q: Do I need to prime the OSB boards with resin first?
A: You will prime your boards during the lamination process (see our roofing guide for details). This process is efficient, by laying the matting onto wet resin before wetting out the first layer you are encourage the resin to be absorbed both underneath and on the top, this results in a good saturation.
Q: What is the difference between Flow coat and Gel Coat, can either be sprayed to produce a water tight finish?
A: Flow coat is a Gelcoat, with a wax in styrene additive for use as a Top Coat. Gel coat can be sprayed providing that it is "spray gel coat" not hand lay gel coat. It is not common practice to use a spray system for roofing applications.
Q: Are redundant GRP based products classified as special wastes or can they go to landfill?
A: Redundant GRP based products can go to landfill as long as the resin products are fully cured beforehand. It is important to check with your local landfill site on their regulations.
Q: Is the CYB Roofing system BBA accredited?
A: At this stage our roofing system is not BBA accredited. The cost to have such accreditation is huge and owing to the current financial climate we are trying to keep our raw material cost down so that our end user can benefit. We have had a number of meetings with the BBA and will certainly look at the accreditation in the future. CYB Ltd have been in the Glassfibre Industry for over 50 years, initially manufacturing 100s of small cruisers (Jaguar Yachts). This experience gives our company the added advantage of stored knowledge regarding the uses and advantages of using Glassfibre within the roofing industry.
Q: My architect has recommended that I use GRP for my flat roof but hasn’t specified what materials to use. What do I do regarding building regs?
A: Many architects are recommending the use of Glass Fibre (aka GRP) on roofs of today to eliminate the use of heat applied products. We are happy to help with any planning applications to ensure that the correct materials are used as per the building regs (some areas insist that fire retardant resins are used but others don’t). All of our materials are of the highest, Lloyds approved standard. Please do not hesitate to contact our offices to discuss your project.
Q: What is the life expectancy of a GRP roof?
A: The life expectancy of a GRP roof (if applied properly) is over 25 years. We still have yachts in the water that we built over 30 years ago, you can visit the website http://myweb.tiscali.co.uk/westgatefamily/default.htm The Current Co-Director of CYB LTD (Eric Birch) built every size Jaguar on this site except the Jaguar 27. They have been manufactured by another builder since 1996. Our suggested application of materials for your GRP is based around the manufacture of these boats.
View More FAQ's
» Resins
» General Fibreglass
» Fibreglass Boats
» Gel Coat
» Car Repairs
» Fibreglass Pond Building
» Fibreglass Roofing