Introduction
GRP systems have been around for many years, but were never 'really' tailored for roofing requirements. Customers would generally favour the more traditional methods of bituminous felt roofing, probably in reaction to contractors lack of experience with GRP.
So now that GRP had made a strong impact on the UK roofing scene, will the shock waves make felt flat roofing extinct?
The short answer is no.
Although there are many advantages to using GRP on your flat roof, some traditionalists still opt for felt systems over the new fibreglass system.
Why?
Two main reasons really, cost and proven reliability.
Felt systems are cheaper to install than the shiny new GRP system. The cost difference can be as much as £30 per metre.
GRP carries 20 year guarantees (25 in some cases), but hasn't been around long enough to test these lengthly guarantees. Most customers of ours who opt for felt systems, are changing like for like (felt off, felt on). Most of them have lived with their felt roofs for 10 years plus, and that, paired with the cost savings, is good enough for them.
So the felt industry doesn't need to board up the hatches just yet, but is GRP a better system?
In our opinion, GRP is a better system for a number of reasons. Firstly, a new deck MUST be installed when GRP is applied, so the extra costs are justified by a brand new roof deck, which would include inspection of those rotting joists underneath the existing deck. Most contractors lay felt systems over the existing deck (after stripping the covering), which does not lend an opportunity to inspect the insulation properties. With all of the recent noise regarding minimum insulation requirements, it can be advantageous to know what is underneath your roof deck. After all, once the new roof is installed, you would have lost your chance to top up insulation.
Secondly, GRP is seamless. It is liquid applied, and although fibreglass mat is consolidated to form the covering, the mat merges to the next sheet forming a seamless roof covering.
Thirdly, GRP is more flexible. So if you have a flat roof with protruding pipes or window detail, GRP can be manoeuvred much easier than its felt rivals.
More advantages of GRP
- GRP is cold applied, meaning no need for heat works, and additional insurances on your property. Fire risk is minimal with felt systems, but does exist all the same.
- GRP is aesthetically pleasing. We have achieved some very pleasing finished to GRP projects (if that's what you like). It is also available in a few different colours.
- It has a 20 year guarantee. Regardless of its proven sustainability, the guarantee exists. So read it through, ask for an example guarantee, and if possible.. Make it insurance backed in case of your contractor going out of business in the years to come.
So there are a few reasons, why we recommend GRP over felt.
I hope this guide helps.
By Nicky Morris
Barris Roofing Ltd
www.roofingsouthlondon.co.uk
