Information to help choose the right GRP roofing products and services.

You should only need to add a fibreglass roof to your property once, let's get it right the first time!

GRP or fibreglass is one of the most popular flat roofing systems in the UK, over the past five years we've seen a sharp increase in companies applying, teaching and selling this product. Unfortunately, its increased popularity has flooded the market with lower-grade materials, inferior training and poor quality workmanship.

The bitterness of poor quality remains long after the sweetness of a low price is forgotten.

We've all heard the stories of rogue contractors, they're in every industry, including GRP roofing and our approved contractors are called out regularly to help the victims of these rogue roofers.

The most common problems associated with GRP roofing are down to the use of inferior grade materials and poor quality installation. By the time you get an issue with your new roof, the contractor will either want nothing to do with you or may not even be trading anymore.

Each time this happens it causes no end of stress and upheaval, we've seen homes damaged, possessions ruined and tempers frayed.

This guide will arm you with the information you need to make the right choices.

With so many different GRP roofing systems on the market, it’s hard as a consumer to know what you're getting for your money. In this impartial guide, we'll show you what to look out for when choosing the right materials and how to put the right checks in place when interviewing contractors for the job.

Here’s everything you need to know about saying yes to your new GRP roof.

This guide will provide some clarity, but there's still no substitute for talking to a professional who can inspect your property and recommend the right product for the job. If this guide still leaves you with questions, please pick up the phone and contact one of our team.

Choosing the right materials

Buying the highest quality products for your GRP roof might cost more money, to begin with, but could save you a tonne of headaches and a possible damaged reputation in the long term.

With the choices out there in the industry, it's often hard to know what system to go for and what's the best one for your roof. In this section, we've listed a few of the most important things to look for when buying materials.

Resin system

In order to cheapen the product, some companies offer a “standard” or “low-cost” material which hasn’t been specifically adapted for the market and could be an inferior grade product. Always buy a flexible system and follow regulations by using a tested and fire-retardant product where necessary.


Use either 1 layer of 600gm or 2 layers of 450gm fibreglass matting for added protection. Applying just 1 layer of 450gm on a large roof uses around 0.5 kgs of resin less per square metre, which could compromise the overall strength. For more information check out our GRP roofing fibreglass guide.

Check the dates

All standard GRP roofing resins and topcoats have a relatively short shelf-life and depending on how they’re stored will last between 2 and 6 months. Check the manufacture date which should be clearly marked on the label and make a note of the batch number so that if anything goes wrong you can go back to the stockist armed with the information they need.

Choosing the best contractor

Due to the popularity of GRP fibreglass roofing over the past few years, we've seen a dramatic increase in the number of untrained contractors offering GRP roofing services. In this section, we'll give you some things to look for when picking a contractor for your flat roof.

If it’s too good to be true, then it probably is!

Get a minimum of 3 quotes from different companies around the area, always be wary of people who give you a price over the phone without looking at the job and watch out for contractors who say they can go over the top of the existing surface without the need to strip and re-board.

Get the quotations on the company’s letterhead which should display the contact details, address and trading name. Wherever possible make sure that the quotes are for fixed-price terms and if the tradesman is VAT registered check to see if this is added to the final total.

Picking the cheapest quote is not always the best option, if the price is too good to be true, then it usually is. Make sure you do your research on the contractors and even though they can be falsified, check for any verified online reviews.

Ask for training records

With GRP roofing materials so readily available, anyone can claim to be an expert so always ask to see your contractor's training certificate. If the certificate shows a company name or brand follow that up online and find out what the course details are. A lot of bad habits and cut corners have appeared in GRP roofing over the last couple of years, mainly down to the lack of quality training being provided.

Do a product check

Before going ahead with a GRP fibreglass roofing job it’s always a good idea to ask what brand or system your chosen contractor is using and to make sure they have specified the correct reinforcement and fire retardant product to meet regulations.

Check the insurance

Always make sure that anyone you employ is insured and always ask to see up-to-date certificates before starting work. If an accident does happen and your contractor isn’t insured it could come back to bite you.

Guarantees and warranties

Find out what the guarantee or warranty covers, if it’s just a manufacturer's guarantee and the products are found to be at fault, then the company will just replace the materials.

If it's a contractor error and the company has gone bust within the manufacturer's guarantee period then you will not be protected. Check the small print of the guarantee and see what exactly your roof is covered for. Always make sure you get both manufacturer backing and contractor insurance backing for the roof.