EPDM vs GRP Flat Roofing: Which Is Better in Kent?

EPDM and GRP are the two best options for modern Kent flat roofs. They are both vastly better than traditional felt, but they have different strengths. Here is the honest comparison.

Cost (2026 Kent Pricing)

• Built-up felt (for comparison): £55-£85/sq m
• EPDM rubber: £75-£120/sq m
• GRP fibreglass: £95-£145/sq m

For a typical 12 sq m garage roof:

• Felt: £900-£1,500
• EPDM: £1,200-£1,900
• GRP: £1,400-£2,200

GRP costs roughly 20-30% more than EPDM for equivalent area.

Lifespan

• Felt: 15-25 years
• EPDM: 30-40 years
• GRP: 25-35 years

EPDM has a slight edge on raw lifespan, but both vastly outlast traditional felt.

Installation

EPDM is supplied as a single sheet pre-cut to your roof size. It is bonded to the deck with adhesive, with no seams on most domestic-sized roofs. Quick install (1-2 days for a garage), low waste.

GRP is applied wet, fibreglass mat layered with resin, finished with a topcoat. Slower install (2-4 days for a garage), more weather-dependent during cure.

Walkability

EPDM is rated for occasional access (maintenance walks). Heavy regular foot traffic damages it.

GRP is genuinely walkable. If you want a roof that doubles as a balcony or regularly walked surface, GRP is the choice.

Aesthetics

EPDM is matt black. Some products offer textured topcoat options but choice is limited.

GRP can be supplied in any colour and finish. Common choices include grey, slate, and even tile-effect for visible roof areas.

Detail Work

EPDM handles corners, upstands, and complex shapes with prefabricated trim sections. Skill required is moderate.

GRP can be applied seamlessly around any shape, but the wet application requires more skill to get right. Bad GRP installs are easy to spot, wavy surfaces, visible mat texture, runs and drips.

Repair

EPDM is straightforward to repair, bond a patch over the damage. Permanent if done right.

GRP repairs require sanding back, re-laying mat, re-coating. More involved but stronger long-term result.

Which Should You Choose?

Choose EPDM if:

• Budget is a primary driver
• The roof is hidden from view
• Quick installation matters
• The roof won't be regularly walked
• You want maximum lifespan per pound spent

Choose GRP if:

• The roof is visible and you want it to look like more than a black sheet
• You want occasional/regular foot traffic
• You want a specific colour
• You have a complex roof shape
• You're willing to pay 20-30% more for the better finish

Get Both Quoted in Kent

We quote both EPDM and GRP options on flat roof jobs across Canterbury, Margate, and Folkestone. Call 07562690714 or request a quote.