• GRP Fibreglass Roofs
  • GRP Fibreglass Roofs
  • GRP Fibreglass Roofs

GRP Fiberglass Roofs in Plymouth

GRP fibreglass roof

Flat roofs made from fiberglass are not an uncommon sight and have been around in the UK for 30-years plus, however, only recently in the last 10-years has the Glass Reinforced Plastic system roof, or better known as GRP system, has really grown and due to the advanced technologies in GRP interest for this roof system has increased exponentially. The incorrect use of hard bot resins instead of formulated roofing resins leading to poor installation technics in the early days deterred many people from using the system. Nowadays approved installation techniques and methods of creating a join less flat roof have lifted this flat roofing system to new heights and it is now very sought after and desirable.

The layers consist of:
  • Plywood Decking and glassfibre bandage
  • Glassfibre layer
  • Top coat
  • Non slip aggregate (Optional)
The Positives to a GRP roof:
  • Lightweight
  • No hot flame or heat during installation
  • Very tough and hard wearing
  • Resistant to vandalism
  • Long lifespan
  • Joint less / seamless surface
  • DIY friendly
The Negatives to a GRP roof:
  • Not all that flexible
  • Not suitable for large surfaces areas easily
  • Can be slippery when new
  • Weather has to be dry and not below 41 degree Fahrenheit.

Lead work and drip-beaded edges are used to complete all our flats roofs as required and necessary. If you decide you want to ensMost companies will provide you with a 20 to 25-year guarantee as there is usually no problems whatsoever with these systems if they are correctly installed. There are GRP roof about that are 30 years old and the only signs of wear was slight discoloration fading to the final topcoat.

Some facts regarding a GRP System

The cost is usually more expensive than a felt roof EPDM rubber roof and is dependent on the specification required such as the final finish option and lamination thickness.

The suitability purpose has different aspects, its lightweight and good for green roofs, attractive to look at, completely joint less, can be used with an abundance of different shapes and comes in practically any colour. Its not really suitable for extremely large areas especially if the roof of flimsy design and can be prone to contraction and expansion from weathering conditions. Not hot works are necessary for its installation.

It is robust and can hold up against continuous footfall but without an anti slip coating it will be slippery. It is impermeable to most forms of abuse such as vandalism and knife slashes.

Repairs can vary from a complete new layer directly applied and bonded to the top layer to a small patch repair. Most repairs if done correctly are practically invisible.

Look wise, you cant really beat it. With a huge choice of colours for the final coat to choose from you can even blend it in with the main colour of your house. It’s easily cleaned with just soap and water.

The only installation problem really is that the weather must be dry and over a certain temperature and not below 41 degree Fahrenheit. These roofing systems cannot be installed in cold frosty conditions. If you are supplied a quotation and it is considerably cheaper than the other installers just be aware the reason could be due to a lesser quality thickness material being used combined with a poorer installation technic method to install.

It is DIY friendly and small roof coverings can be installed by a competent handyperson. There is lots of guidance available on YouTube.

GRP fibreglass roof
The installation Process

A GRP fiberglass roof installed and laid correctly can last up to 30-years with no apparent visible signs of deterioration apart from discoloration. The existing roof has got to be dry and at a temperature not below 41 degree Fahrenheit. The material resin coats should be approved products to use for a GRP roofing system.

The information guide we provide here only relates to the application of the GRP lamination and topcoat. Given a 20 sq/m roof two men usually will be able to strip back the old roof, renew the decking, laminate and then apply the topcoat all in just one day. Every installation needs to be planned during a known period of settled dry weather.

Just a few of the colours available
Some of the colours available
The Decking

Tongue and groove OSB3 Sterling Board decking should be used, this needs to be fixed down with either screws or ring shanked nails to a minimum depth penetration of 25mm and spaced at 300mm apart throughout the entire length of the roofing joist the board is being fixed to. Make sure that the boards are laid in a staggered fashion and laid the correct way around with the gap between the boards facing upwards so as the resin can flow into the gap reinforcing it when the lamination is applied. Next is to fix the edge trims.

Edge Trimming

Edge trims are available in GRP. One side is glossy the other is a matt finish. The side always used to fix or bond is the matt finish side so as the glossy side is on show. The majority of trims can fixed with staples or nails directly to the decking boarding apart from the angle fillet and flat finish trims, these have to be bonded into place using a suitable adhesive not off the shelve mastics or general purpose silicone sealants.

Any joining of the trims needs to be overlapped and bonded and bandaged together using a suitable adhesive again not off the shelve mastics or general-purpose silicone sealants. The correct adhesive to use would be a Polyurethane Adhesive. A drip fascia trim can be fitted in an offset manner to maintain that the drip can stand over the guttering. Mitres can be cut to form corners or manufactured corners can be purchased. The corners will require sealing in place on site using a section of fiberglass.

GRP fibreglass roof
The Lamination

It is of vital importance that the lamination is carried out when you know the outcome of the weather forecast and have determined the air temperature. Depending on the air temperature can even affect the size roof you are going to tackle.

A small roof can be carried out on a hot day but longs runs are better to perform on cooler days as the resin will cure at a quicker rate on a hot days in hot conditions, so the glass you actually lay down will be dependent on the temperature conditions. Either way or method the air temperature must not be below 41 degrees Fahrenheit at all.

The glass resin ratio needs to at 1:2:5

Pre cut the glass to the correct sizes and length prior to applying the laminate. Remember to use smaller lengths the hotter the air temperature is. When laying the laminate there is no specific way it should be laid and it really is not important as in which direction the joints are lapped. Ensure the roof is clear of all debris and not needed items, mix the necessary amounts of catalyst with the resin enough to complete the first sections or run.

Wet down the area to be treated then simply roll out the glass. Apply the resin mix to the glass then once allowed to wet out for a minute or two amalgamate the glass using the roller making sure that there are no dry areas of glass left and to ensure that no air has been allowed to get trapped in the laminate.

Avoid stepping onto wet resin and glass while repeating this method for the next section or run overlapping each time by at least 50mm. Continue until the whole roof has been coated completely ensuring the laminate has fused well together.

GRP fibreglass roof
Top Coat

It is now essential that the laminate now laid be top coated asap. It is not recommended to leave the laminate for long periods like overnight and wait until the next day. The laminate can be tested for cure by exerting slight pressure on it using your finger. When it is not possible to move the glass fibres in capsuled in the resin it is approximately half cured. It will now be able to endure light footfall meaning it is now possible to complete the final topcoat.

Sometimes it may be necessary to be working alone, if this is the case then we suggest you transfer the topcoat into separate buckets keeping the amount in each bucket to around 3 kilograms which is sufficient to cover approximately 6sq/m. Prepare one mix at a time, add the catalyst and apply with the roller maintaining a wet edge at all times. Once the bucket is empty move straight on and catalyse the next bucket and continue from where you left off. Keep a small amount over to complete the edges and fine details.

The topcoat should be of an even layout and no more than half a milometer in thickness. If the topcoat is laid too liberally there is a high probability of cracking occurring. Your new GRP roof is now finished. It will take a further week to completely cure. It can be cleaned with a brush, soap and water. Bleach or strong alkali is definitely not recommended. It will hold up under footfall and can have planters and pots on with no damaging affects. It will last a long time without deterioration. Only from time to time you may find it necessary to decorate the edge trims.

Catalyst additions or amounts:
  • Do not use less than 1% even in hot conditions. If a smaller amount is required then mix less.
  • Do not use more than 4%. Adding more catalyst will not effect or reduce the curing time.
  • Do not underestimate the effects air temperature will have. If the air temperature is too low the resin will not cure. It will also cure faster in direct sunlight.
  • Top tip is to add more catalyst if top coating quite late in the afternoon to allow for the low intensity of sunlight.
  • Catalysts are manufactured in different strengths so as adapted to be used for the specific seasons for summer and winter.
  • If they is left over catalysts in the bucket it will react and go exothermic. As it cures it generates heat so it needs to be stored in a safe place away from other items or materials. It may be a good idea to pour some water over it to suppress any heat being generated.

If this guide is not followed you may well encounter a few issues and problems cropping up during laying the GRP and once its completed. These are some signs and symptoms.

  • If there is moisture in the deck during lamination it will cause – The delamination of the laminate.
  • Applying the topcoat too thickly or applying it onto wet laminate will cause – Cracking & Flacking of the topcoat.
  • If the air temperature is too hot to apply the resin, or if too much catalyst is added it will cause – The resin to cure too fast.
  • If the air temperature is too hot to apply the resin, or if too much catalyst is added it will cause – The topcoat to cure too fast.
  • If the temperature is too low or no catalyst has been added it will cause – The resin to cure far too slowly or worse, not at all.
  • Not enough Catalyst and improper mixing can cause – Streaky or patchy cure of topcoat or resin.
  • Water contamination can cause – The Resin to appear milky white and will not cure.
  • A lacking of consolidation together with not enough resin can cause – Extreme fibre patterns.

If your having any problems or for more information please feel free to contact Acorn Roofing Solutions (ARS) 01752 201077 where a member of our staff will be happy to talk with you and give you some free advice

Contact us
Acorn Roofing Solutions (ARS) are here to help all Domestic Customers with their GRP roofing issues

We provide a complete piece of mind service for our private sector clients and our commercial sector clients. Weather it’s a new project build, an old property needing some TLC or just a maintenance repair. Call us you wont be disappointed.

Our experienced surveyors are ready and waiting to make an appointment pop out and survey the proposed project in question. We can as necessary include detailed design and build drawings, structural calculations and U value calculations. We will advise you on rainwater goods, running outlets, insulation and specify the correct roofing material most suitable for your requirements and budget.

Once we know your needs and specifications our qualified tradesmen team of professional technicians will arrive on your door and perform the work require causing you as minimum disruption as possible.

Places GRP roofing system can be found:
  • Roof terraces & gardens
  • Balconies
  • Deck structures
  • Car parks
  • Roof valleys and gutters
  • Flat & small pitched roofs
  • Inverted roofs such as Green and brown roofs
Please feel free to contact us for help or advice
Call today

If you are interested in booking a survey for any of our services or just a roof safety check, please contact Acorn Roofing Solutions (ARS) and a member of our team will be happy to help or advise you.

CALL – Acorn Roofing Solutions (ARS) now on 01752 201077

All Our Services
  • Tiling
  • Slating
  • Felting flat roofs
  • Lead work
  • Lead flat roofing
  • GRP fibreglass flat roofs
  • Rainwater goods (Guttering & downpipes)
  • PVC Fascia, soffit, & barge boards
  • Velux roof windows
  • Fakro roof windows
  • Sky lights
  • Sun tunnels
  • Loft conversions
  • Loft ladders
  • Green roofs
  • Liquid applied roofing
  • Solar PV installations
  • Chimney rebuilds & repairs
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  • Why Choose Us
    Why Choose Us?
    We are big enough to take on any challenge yet are small enough to provide a personal service. We give a reliable service that is cost effective without sacrificing quality.
  • Our Experience
    Our Experience
    Our team specialise in a first class finish. We only employ highly skilled professionals who have ample training and experience in their specialist fields. We are extremely proud of our reputation of timely, tidy, respectful, and focused employees.
  • How We Work
    How We Work
    We support you from start to finish, focusing on providing the best value for money we analyse your requirements, provide you with the options available to you and work to your needs and budget without forfeiting quality and sustainability.