Fibreglass price guide

Ive been using a fibreglassing specialist to do orangery roofs.

The latest job has been invoiced, £2,280+vat.

Job size 15 sq metres (includes upstands etc).

We prep the roof ready for fibreglassing, arris rail, trims etc. No trims, flashing required after.

How much would you say the job should be or price per square metre

Without seeing the roof £152 per square metre does seem high for a 15 square metres.

• Do you know what GRP roofing system they are using on the roof? are they trained and approved with a specific system or do they just buy the cheap stuff from a builders merchants?
• Do they offer a guarantee and is it insurance backed?

Rufus Raintight said:

Without seeing the roof £152 per square metre does seem high for a 15 square metres.

• Do you know what GRP roofing system they are using on the roof? are they trained and approved with a specific system or do they just buy the cheap stuff from a builders merchants?
• Do they offer a guarantee and is it insurance backed?

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I dont know what they use. Its matting with resin, then lead grey gel coat. They def buy from an industrial / trade supplier.

Is there a difference in quality of product?

The company has a workshop and makes tanks, and also builds commercial water features..

Ive used them for years and like most subbies, they do the job and invoice me. They used to charge around £75/ sq metre. But it crept up slowly, then the last job was invoiced as mentioned.

Im sure they dont do insurance warranty, or provide a guarantee although they always go back if there is a problem. I dont suppose insurance warranty would be common business to business.

I offer insurance back warranty to the customer.

Notch7 said:

Is there a difference in quality of product?

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Oh yes!! you can buy some real cheap and nasty stuff!. If they make tanks, and water features they could be using the same general purpose GRP resin system which can be used on roofs but won't necessarily have been fire tested or won't have the added flexibility, to enable it to expand and contract as easily.

Questions you need to ask your contractors

• Can you provide the fire certification for the roofing system they used or ask them what brand of resin was it?
• Do they use 450gm fibreglass matting or 600gm matting (600gm makes for a stronger roof and uses more resin - which means it costs more)

A really good contractor that's an approved installer of a certified, fire tested, flexible system would charge anything between £85 - £200 per square metre depending on system and your location, but for this they would strip and relay the deck with fresh OSB3 and provide and install all the trims, you would also get an insurance backed guarantee for the contractors workmanship and a manufacturer backed guarantee for the materials.

If all a contractor is doing is going onto a roof and applying the system then it should be no more than £100 per square metre, obviously depending on the roof etc..

You need to dig deeper and find out what resin system they used and the type of glassfibre they put down. If they used top notch gear on the roof then the price is understandable, but if they are just using a standard GRP resin system not to mention you did all the prep work, then that price is really high.

Check out this GRP roofing buyers guide, if gives some more info on what to look for when choosing contractors and materials https://www.grproofing.com/buyers-guide

Rufus Raintight said:

system which can be used on roofs but won't necessarily have been fire tested or won't have the added flexibility, to enable it to expand and contract as easily.

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Many thanks for your advice, Ive browsed the link and will investigate further.

Are there any brands you recommend for the resin or trade suppliers?

Ive now swapped to using a guy who is a roofer and does fibreglassing, I do know he learnt fibreglassing trade from working on boats, bu tI dont know what he uses on the roofs. I shall be doing some more research. Ive no objection to paying the right money for the best materials, but its not always easy to find out what the means in practice.

The biggest problem we have is the weather, normally rain is the issue, but recently too much sun....

The resin used for boats is different from the resin used for roofs.
I think roofing resin has an extra ingredient to make it more flexible to cope with expansion and contraction when it is stuck to the roof deck.