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What Material is Best for a Flat Roof in 2026?
- Aug 22, 2025
- 4 min read
Updated: Jul 3
Flat roofs are used on everything from homes and apartment blocks to schools, offices and commercial buildings. But with so many roofing systems available, choosing the best flat roof material isn't always straightforward.
The right roofing system depends on several factors, including the type of building, your budget, how long you expect the roof to last and whether you're refurbishing an existing roof or installing a completely new one.
In this guide, we compare the most popular flat roof materials, explain their advantages and disadvantages, and help you decide which roofing system is best for your building.
Which Flat Roof Material Is Best?
There isn't one flat roof material that's best for every building.
The most suitable roofing system depends on:
The type of property
The condition of the existing roof
Your available budget
The expected lifespan
Future maintenance requirements
Whether the roof is being repaired, refurbished or replaced
For many commercial refurbishment projects, modern torch-on felt and liquid-applied waterproofing systems provide an excellent balance of durability, value and long-term performance. EPDM is often chosen for larger new-build roofs, while GRP remains an excellent solution for balconies and smaller flat roofs.
Flat Roof Material Comparison
Roofing System | Typical Lifespan | Best For |
Liquid Waterproofing | 20–30+ years | Refurbishments, balconies, complex roofs |
Torch-On Felt | 20–30 years | Schools, housing associations, commercial buildings |
EPDM Rubber | 40–50 years | Large flat roofs and new-build projects |
GRP / Fibreglass | 30–50 years | Balconies, terraces and smaller roofs |
Green Roof | Varies | Sustainable developments |
Want to know how long each roofing system lasts? Read our guide: How Long Does a Flat Roof Last?
EPDM (Ethylene Propylene Diene Monomer) is a single-ply rubber roofing system. It’s lightweight, flexible, and highly durable.
✅ Pros: Lasts 40–50 years, easy to maintain, eco-friendly, safe installation (no flames required).
❌ Cons: Plain black appearance, edges must be finished carefully.
💷 Cost: Around £70–£110 per m² (installed).
👉 Best for: Large commercial roofs, new-build developments and buildings where a low-maintenance roofing system is required.
GRP (Glass Reinforced Polyester), also known as fibreglass, creates a seamless, durable finish that can last for decades.
✅ Pros: Very strong, seamless finish, available in colours, ideal for balconies and terraces, 30–50 year lifespan.
❌ Cons: Requires skilled installation, can crack if poorly applied.
💷 Cost: Around £90–£150 per m².
👉 Best for: Balconies, terraces, walkways and smaller flat roofs where a seamless finish is required.
Torch-On Felt
An upgraded version of traditional felt, torch-on modified bitumen is applied using a gas torch.
✅ Pros: More durable than standard felt, flexible, performs well in cold weather, life span of 20–30 years.
❌ Cons: Requires naked flame installation, so must be done by professionals.
💷 Cost: Around £60–£100 per m².
👉 Best for: Schools, housing associations, commercial buildings and public-sector refurbishment projects.
Liquid-Applied Waterproofing
Liquid-applied systems are one of the most popular solutions for refurbishing ageing flat roofs because they can often be installed directly over suitable existing waterproofing, reducing cost and disruption.
✅ Pros
Seamless waterproof finish
Excellent for complex roof details
Cold applied (no hot works)
Ideal for refurbishment projects
Long-term manufacturer warranties available
❌ Cons
Requires correct preparation
Must be installed by trained specialists
💷 Cost: Around £80–£140 per m².
👉 Best for: Commercial buildings, schools, housing associations, balconies and flat roof refurbishment projects.
Green / Living Roofs
Green roofs are a sustainable option that use vegetation to cover the roof surface.
✅ Pros: Eco-friendly, natural insulation, attractive appearance, reduces energy bills, supports biodiversity.
❌ Cons: Higher upfront cost, requires a strong structure to support the extra weight.
💷 Cost: Around £80–£200 per m².
👉 Best for: Eco-conscious projects, modern developments, or roofs visible from above.
Premier Roofing & Construction's Recommendation
At Premier Roofing & Construction, we install a wide range of flat roofing systems across Essex, London and Kent.
Rather than recommending the same roofing system for every project, we assess the building, its intended use and the condition of the existing roof before specifying the most appropriate solution.
In general:
Commercial refurbishments – Liquid-applied waterproofing or high-performance torch-on felt.
Schools and housing associations – Torch-on felt or liquid systems, depending on the existing roof.
Balconies and terraces – GRP or liquid waterproofing.
Large new-build roofs – EPDM or other single-ply membrane systems.
Environmentally focused projects – Green roof systems where appropriate.
Every roof is different, so we'll always recommend the most appropriate solution based on the building, budget, expected lifespan and long-term maintenance requirements.
Final Thoughts
The best flat roof material isn't necessarily the one with the longest lifespan or the highest price.
Choosing the right roofing system means balancing durability, budget, building use and future maintenance requirements. A system that performs exceptionally well on one building may not be the best solution for another.
If you're unsure which flat roof material is right for your project, professional advice before work begins can help avoid unnecessary costs and ensure the roof performs as expected for many years to come.
Not sure which flat roof material is right for your building? Request a site visit and we'll assess your roof, discuss your requirements and recommend the most suitable roofing system for your project.
