BEST Flat Roofing South London | GRP & EPDM Roofs Croydon

Expert Flat Roofing in South London: GRP Fibreglass & EPDM Rubber

Q: Can you put a new flat roof over an old one?

While it is physically possible, we strongly advise against it. Over-boarding traps moisture in the old roof and hides rotting timber. We always strip the roof back to ensure a long-lasting result.

Q: Why is water pooling on my flat roof?

Ponding water occurs when a flat roof doesn't have enough fall for the water to run off. We always aim to correct the fall of the roof during the re-decking phase to ensure proper drainage.

Say goodbye to leaking felt roofs. We install seamless, highly durable flat roofing systems for extensions, garages, and dormers across Croydon and Bromley.

If you own a home in South London, there is a very good chance you have a flat roof somewhere on your property. From classic Victorian terrace kitchen extensions in Croydon to modern garage conversions in Bromley and dormer loft conversions across Surrey, flat roofs are incredibly common.

Unfortunately, they also have a terrible reputation. For decades, the standard material for flat roofs in the UK was traditional poured bitumen and roofing felt. While cheap, traditional felt is highly susceptible to the drastic temperature changes of the British weather. It expands in the summer sun, contracts in the winter frost, and inevitably blisters, cracks, and leaks within 10 to 15 years.

At HLS Roofing, we do things differently. We specialize in modern, seamless flat roofing systems—specifically GRP (Fibreglass) and EPDM (Rubber). These advanced materials offer incredible durability, remaining completely watertight for decades.

The Problem with Traditional Felt Flat Roofs

If you are currently dealing with a leaking flat roof, you are likely suffering from the inherent flaws of old-fashioned felt. Felt relies on seams and joints being melted together with a blowtorch. Over time, standing water (ponding), UV rays, and frost break down these seams. Once water gets beneath the felt layer, it rots the timber decking below, leading to major internal leaks.

While we can perform an emergency roof repair on a felt roof to stop an active leak, if the roof is over 15 years old, patching it up is usually a false economy. We highly recommend upgrading to a modern, joint-free system.

GRP Fibreglass Flat Roofing: The Ultimate Protection

GRP (Glass Reinforced Plastic), commonly known as fibreglass, is one of the most robust flat roofing systems available today. It is the same material used to build the hulls of boats, making it entirely impervious to water.

Why Choose a GRP Flat Roof?

Completely Seamless: GRP is applied as a liquid that cures into a solid, continuous shell over your roof. There are zero joints, seams, or welds where water can penetrate.
Incredibly Tough: Once cured, a fibreglass roof is hard enough to walk on, making it perfect for balconies or roofs that require regular access for window cleaning.
Architectural Finish: It provides a sleek, modern, architectural finish, usually in a dark grey colour that mimics the look of lead.
Long Lifespan: A properly installed GRP roof will easily last 25 to 30+ years with zero maintenance.

EPDM Rubber Flat Roofing: Flexible and Weather-Resistant

EPDM (Ethylene Propylene Diene Monomer) is a highly durable synthetic rubber roofing membrane. It is widely used in commercial roofing across the globe but has become increasingly popular for residential properties in South London.

Why Choose an EPDM Flat Roof?

Extreme Flexibility: Unlike felt, EPDM rubber can stretch and contract massively without cracking, meaning it handles the freezing UK winters and hot summer sun effortlessly.
Single-Piece Installation: For most residential extensions or garages, EPDM can be cut to size and installed as one single, continuous sheet, eliminating vulnerable seams entirely.
Eco-Friendly: EPDM is highly sustainable, often made from recycled materials, and has an incredibly low environmental impact over its lifespan.
50-Year Proven Lifespan: EPDM roofs have been proven to last up to 50 years, offering incredible value for money.

Not sure which system is right for your home? Our experts provide free site surveys in Croydon, Bromley, and surrounding areas to assess your roof and recommend the best material for your specific extension or garage.

Our Flat Roof Installation Process

A new flat roof is only as good as the team installing it. At HLS Roofing, we never cut corners by simply laying new materials over rotting timber. Here is how we guarantee a perfect flat roof replacement:

Full Strip Down: We remove the old felt and inspect the underlying timber decking (the OSB or plywood boards) and joists for water damage or rot.
Re-decking: If the existing decking is compromised, we replace it with brand new, high-grade oriented strand board (OSB3) to ensure a perfectly flat, structurally sound base.
Insulation Upgrades: If your flat roof is above a warm living space (like a kitchen or bedroom), this is the perfect time to upgrade the insulation to meet modern building regulations and lower your heating bills.
Precision Installation: We install your chosen GRP or EPDM system, ensuring perfect detailing around edges, upstands, and roof lanterns.
Lead Flashing: We install new lead flashing where the flat roof meets the brickwork of your main house, ensuring a totally watertight seal.

Frequently Asked Questions (FAQs)

Which is better, GRP Fibreglass or EPDM Rubber?

Both are excellent, modern systems. GRP is harder and more suitable if you need to walk on the roof regularly (e.g., a balcony). EPDM is more flexible and often more cost-effective for simple, large, flat areas like garages. We will advise you on the best choice during our free survey.

How long does a flat roof replacement take?

Most residential flat roofs, such as a standard garage or kitchen extension, can be completely stripped, re-decked, and waterproofed within 1 to 2 days, weather depending.

Can you put a new flat roof over an old one?

While it is physically possible (known as an 'overlay'), we strongly advise against it. Over-boarding traps moisture in the old roof, hides rotting timber, and adds excessive weight to your roof joists. We always strip the roof back to ensure a long-lasting result.

Can I have a skylight or roof lantern installed?

Absolutely. Flat roofs over kitchen extensions are perfect for roof lanterns or flat glass skylights. We can create the necessary upstands and perfectly seal the GRP or EPDM around the new window unit to flood your room with natural light.

Why is water pooling on my flat roof?

Ponding water occurs when a flat roof doesn't have enough 'fall' (a slight slope) for the water to run off into the gutters. While modern materials like GRP and EPDM can withstand standing water much better than felt, we always aim to correct the fall of the roof during the re-decking phase to ensure proper drainage.

Do your new flat roofs come with a guarantee?

Yes, all our new GRP and EPDM flat roof installations come with extensive, long-term guarantees for your total peace of mind. Both materials are designed to last for decades without requiring maintenance.

Areas We Provide Flat Roofing

HLS Roofing provides expert flat roof installations, repairs, and maintenance across South London. Find our dedicated roofing teams in your local area:

Stop the Leaks. Upgrade Your Flat Roof Today.

Don't wait for the next heavy rainstorm to damage the interior of your extension or ruin the contents of your garage. Upgrade to a modern, seamless GRP or EPDM flat roof with HLS Roofing.

Get Your Free Quote Today

Or call us at: 07709 760136