If you are replacing a flat roof, the biggest decision is which system to use, and the four you will most often be quoted for are EPDM rubber, GRP fibreglass, felt and single ply membrane. They all keep the water out, but they differ a lot on lifespan, cost and where they perform best. Here is a straight comparison to help you choose, based on current UK figures.
The short version: felt is the cheapest up front but the shortest lived, EPDM rubber gives the longest life for the money, GRP is a tough seamless finish that suits smaller or trafficked roofs, and single ply is the go to for larger commercial and industrial roofs. The right choice depends on the size of the roof, the budget and how long you need it to last.
EPDM rubber
EPDM is a single sheet of synthetic rubber, usually laid in one piece so there are very few joints to fail. It is the system we most often recommend where longevity and value matter. Typical cost is around £80 to £100 per square metre, and a professionally installed, well maintained EPDM roof can last 30 to 50 years. Best suited to domestic extensions, garages and small to medium commercial roofs where a long, low maintenance life is the priority.
GRP fibreglass
GRP (glass reinforced plastic, or fibreglass) is applied wet and cures into a hard, seamless, walk on surface. That makes it a strong choice for roofs that get foot traffic, balconies and more complex shapes. Typical cost is around £95 to £120 per square metre, with a lifespan of up to around 30 years when installed correctly. It gives a neat finish but needs skilled installation and dry weather to lay properly.
Felt (torch on bitumen)
Modern felt is a big step up from the old pour and roll material, applied in torched on layers. Its main appeal is the lower up front cost. Typical cost is around £50 to £80 per square metre, but the trade off is a shorter life expectancy of roughly 15 to 20 years. A sensible option where budget is the main driver and the roof is not expected to stay in place for decades.
Single ply membrane
Single ply is a thin, flexible sheet (commonly PVC or TPO) heat welded at the seams. It is lightweight, quick to install over large areas and is the standard for warehouses, factories and larger commercial roofs. Cost is broadly comparable to EPDM and GRP depending on the specification, with a typical lifespan of around 20 to 30 years. Its strength is covering big commercial spans efficiently with strong, welded seams.
At a glance
Felt is lowest cost, shortest life. EPDM is best long term value with the fewest joints. GRP is the tough, seamless, walk on option. Single ply is built for large commercial and industrial roofs. For most Leicestershire businesses replacing a commercial roof, the choice usually comes down to EPDM or single ply, and the deciding factor is the size and use of the building.
Not sure which is right for your roof?
The best system for your building depends on its size, its current condition and how you use it, and that is not always obvious from a brochure. Our team will survey your roof, talk through the options in plain English and recommend the system that genuinely fits, not just the most expensive one. Book a free roof health check and we will give you an honest assessment and a clear quote.
Frequently asked questions
What is the longest lasting flat roof material?
EPDM rubber has the longest typical lifespan, at 30 to 50 years when professionally installed and maintained, followed by GRP and single ply at around 20 to 30 years.
What is the cheapest flat roof option?
Felt is the lowest cost up front, at roughly £50 to £80 per square metre, but it also has the shortest lifespan at around 15 to 20 years, so it can cost more over the long run.
Which flat roof is best for a commercial building?
For larger commercial and industrial roofs, single ply membrane is usually the most practical and cost effective choice. Smaller commercial roofs are often best served by EPDM.
How much does a flat roof replacement cost in the UK?
A standard flat roof replacement typically costs between £2,800 and £7,500 depending on size and material, with an average of roughly £75 per square metre. An on site survey gives the accurate figure for your roof.
Which areas does Stace Roofing cover?
We install and replace flat roofs for commercial and domestic clients across Melton Mowbray, Leicestershire and the East Midlands.