Flat Roof Installation | EPDM & GRP Fibreglass

Flat Roofing Explained

Which Flat Roof System Should You Choose?

Riverstone Roofing Ltd installs three flat roofing systems, and the right one depends on the roof rather than on what we would prefer to fit. EPDM rubber lasts around thirty to fifty years, is laid as a single sheet with no seams on most domestic roofs, stays flexible in cold weather and needs no naked flame, which makes it our usual recommendation for extensions, garages and dormers. GRP fibreglass lasts around twenty-five to thirty years, cures rigid and can be walked on, so it suits balconies, porches and anything taking foot traffic. Torch-on felt is the cheapest and shortest-lived at ten to twenty years, and we mostly use it on outbuildings. Whichever system is chosen, the deck is prepared properly and the upstands and trims are detailed correctly, because that is where flat roofs actually fail. Free written quotes, fixed prices, fully insured, guaranteed.

25yr+

System Lifespan

The Service

Modern Flat Roofs,
Built to Last

Today’s flat roofs are a world away from the leaky felt roofs of the past. At Riverstone Roofing we install seamless EPDM rubber, GRP fibreglass and high-performance felt systems on extensions, garages, dormers and outbuildings — engineered with the right falls, insulation and detailing to stay completely watertight for decades.

We’ll recommend the best system for your roof and budget, build in proper drainage, and finish every edge and outlet neatly — then back it with a guarantee.

Seamless & Watertight

Jointless EPDM & GRP systems with correct falls — no ponding, no leaks.

Guaranteed Installation

Fully insured, with workmanship and manufacturer guarantees.

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How It Works

Our Flat Roof
Installation Process

A proper flat roof is all in the preparation and detailing — here’s how we get it watertight and keep it that way.

Survey & System Advice

We assess the deck, the falls and drainage, then recommend the best flat-roof system and a fixed, no-obligation quote.

Strip & Prepare the Deck

We remove the old covering and inspect the timber deck, repairing or replacing any damaged or rotten boards.

Insulation & Falls

Where needed we add insulation (warm-deck) and firrings to create proper falls so water always drains away.

Membrane Installation

Your chosen system — EPDM rubber, GRP fibreglass or felt — is installed seamlessly across the whole roof.

Trims, Outlets & Detailing

Edge trims, drip details, upstands and outlets are fitted for a crisp, completely watertight finish.

Inspect, Test & Clean Up

We check the falls and seal, confirm the roof is watertight, then remove all waste and leave the site tidy.

What We Install

Flat Roof Systems
We Install

We work with all the leading flat-roof systems, so we can match the right solution to your building, budget and how the roof will be used:

EPDM Rubber Roofing

Single-piece rubber membrane with no joins or seams — flexible, hard-wearing and a 30+ year lifespan.

GRP Fibreglass

Seamless glass-reinforced plastic, exceptionally tough and ideal where the roof may take foot traffic.

High-Performance Felt

Modern torch-on built-up felt systems — a reliable, cost-effective option done properly.

Warm-Deck Insulation

Energy-efficient build-ups that keep heat in and prevent condensation forming under the roof.

Rooflights & Lanterns

Flood the room below with natural light — supplied and fitted fully weatherproof.

Drainage, Outlets & Trims

Correct falls, outlets and crisp edge trims so water sheds fast and never ponds.

EPDM Rubber Roofing

Elevate RubberCover Trained Installer

Our company director trained on the Elevate RubberCover EPDM system with Permaroof UK in September 2026. Rubber flat roofs bonded with no flame, usually in one sheet with no joins, and a life expectancy of more than 50 years.

About Our EPDM Roofs

Compare Systems

EPDM, GRP or Felt —
Which Flat Roof Is Right?

We fit all three, and the honest answer depends on the roof rather than on what we would prefer to install. Here is how they compare on the things that matter.

Flat roofing systems compared: typical lifespan, best use, strengths and limitations of EPDM rubber, GRP fibreglass and torch-on felt.
System	Typical lifespan	Best suited to	Strengths	Watch-outs
EPDM rubber	30–50 years	Extensions, garages, dormers and larger simple areas	Laid as a single sheet with no seams on most domestic roofs, stays flexible in cold weather, and needs no naked flame to install	Needs a clean, dry, well-prepared deck, and the trims and upstands have to be detailed properly
GRP fibreglass	25–30 years	Balconies, porches and any roof that takes foot traffic or has a complex shape	Seamless, rigid and hard-wearing, can be walked on, and comes in a wide choice of trims and finishes	Must be laid in dry weather above about 5°C, and is less forgiving of structural movement
Torch-on felt	10–20 years	Outbuildings, sheds and budget-conscious re-covers	Lowest up-front cost, quick to install and straightforward to patch	Shortest life of the three, built up from multiple layers with seams, and heat is applied during installation

Those lifespans assume a correctly prepared deck and proper detailing at the edges and upstands. Poor preparation shortens all three, whichever system you choose.

The Work

Seamless & Watertight

EPDM rubber membrane

GRP fibreglass

Edge & outlet detailing

Questions & Answers

Flat Roof Installation FAQs

The things homeowners most want to know about a new flat roof. Got another question? Just give us a call.

A quality EPDM or GRP flat roof can last 25–30+ years with minimal maintenance — far longer than the old felt roofs they replace.

Each has its place. EPDM rubber suits most flat roofs (seamless, flexible, long-lasting); GRP fibreglass is ultra-tough and great where there’s foot traffic; modern felt is a reliable, budget-friendly choice. We’ll recommend the right one for your roof.

That reputation came from old felt roofs. Modern EPDM and GRP systems, installed with proper falls and detailing, are seamless and extremely reliable.

Most domestic flat roofs are installed in 1–3 days, depending on the size of the roof and access.

Yes — we regularly fit rooflights and lanterns as part of a new flat roof, fully weatherproofed and looking superb.

Always. Correct falls and outlets are essential, so we build in the right slope to shed water quickly and prevent ponding.

Yes — we’re fully insured, with workmanship and manufacturer guarantees on the system we install.

Flat roof installations across Lincolnshire, Cambridgeshire and Norfolk — Spalding, Boston, King’s Lynn, Peterborough, Grantham, Wisbech, Stamford and the surrounding areas.

Where We Work

Flat Roof Installations
Across the Region

We provide flat roof installations for homeowners across Lincolnshire, Cambridgeshire and Norfolk, including Grantham, Sleaford, Stamford, Bourne, Spalding, Boston, Skegness, Peterborough, Wisbech, March, Chatteris, King’s Lynn, Downham Market, Swaffham and Hunstanton. View all the areas we cover, or call 07782 664697 for a free, no-obligation quote.

At a Glance

Riverstone Roofing Quick Facts

Experience: Over a decade of local roofing experience; Riverstone Roofing Ltd incorporated January 2026

Areas Covered: Lincolnshire, Cambridgeshire & Norfolk

Services: New roofs, pitched & flat roof repairs, leadwork, chimneys, fascias & guttering, roof cleaning

Availability: 24/7 emergency call-outs · Free, no-obligation quotes

Credentials: Fully insured roofing contractor

Contact: 07782 664697 · contact@riverstoneroofing.co.uk

Get In Touch

Get Your Free
Roofing Quote

Tell us what you need and we’ll get straight back to you with a free, no-obligation quote — or call us any time, day or night.

07782 664697

Free QuotesFully Insured24/7 Cover

Flat Roofs That
Stay Dry.

Which Flat Roof System Should You Choose?