If you’re replacing a flat roof, one of the most common questions is whether to choose traditional felt roofing or a modern GRP fibreglass system.
Both have their place, but there are some important differences.
What Is Felt Roofing?
Felt roofs have been used for many years on:
- Garage roofs
- Extensions
- Bay windows
- Porches
- Flat roof sections
Over time they can develop:
- Cracks
- Split joints
- Blisters
- Water pooling
- Repeated repairs
Many homeowners contact us after patch repairs have failed.
What Is GRP Roofing?
GRP stands for Glass Reinforced Plastic, often called fibreglass roofing.
Unlike felt, GRP creates a seamless waterproof finish bonded to the roof deck.
Benefits include:
✓ Strong waterproof layer
✓ Modern appearance
✓ Low maintenance
✓ Long lifespan
✓ Clean finish
Lifespan Comparison
Felt Roof
Typical lifespan:
Around 10–15 years
This depends heavily on installation quality and exposure.
GRP Roof
A professionally installed GRP roof can last:
20–30+ years
Preparation and workmanship make a big difference.
Appearance
GRP roofs usually provide:
- Cleaner lines
- Smooth finish
- Modern look
- Better detail work
This makes them popular for garages, extensions and visible flat roofs.
Which Is Better?
If you want the cheapest upfront option, felt may work.
If you want:
- Longer lifespan
- Fewer repairs
- Better appearance
- Long-term value
GRP fibreglass roofing is often the better investment.
At GRPShieldPlymouth we specialise in GRP flat roofing across Plymouth and Devon with a focus on quality workmanship and long-term results.