--- title: "Flat Roofing in Bishop's Stortford | EPDM, GRP & Felt | J&Co" description: "Flat roofing specialists in Bishop's Stortford & Hertfordshire. EPDM, GRP fibreglass and felt systems with 25+ year lifespans. CRC certified. Free quotes." lang: en-GB json-ld: | [ { "@context": "https://schema.org", "@type": "Service", "serviceType": "Flat Roofing", "name": "Flat Roofing in Bishop's Stortford & Hertfordshire", "description": "Flat roofing specialists in Bishop's Stortford & Hertfordshire. EPDM, GRP fibreglass and felt systems with 25+ year lifespans. CRC certified. Free quotes.", "provider": { "@id": "https://jandco-contractorsltd.co.uk/#business" }, "areaServed": [ { "@type": "Place", "name": "Bishop's Stortford" }, { "@type": "Place", "name": "Hertfordshire" }, { "@type": "Place", "name": "Essex" } ], "url": "https://jandco-contractorsltd.co.uk/flat-roofing/" }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "How long does a new flat roof last?", "acceptedAnswer": { "@type": "Answer", "text": "EPDM and GRP systems installed properly routinely last 25+ years and carry manufacturer guarantees of 20–25 years. Modern three-layer torch-on felt typically gives 15–20 years. Lifespan depends heavily on installation quality and the underlying deck — done badly, any system fails early." } }, { "@type": "Question", "name": "Can you install over the existing flat roof?", "acceptedAnswer": { "@type": "Answer", "text": "Almost never advisable. Overlaying traps moisture in the old covering, hides deck issues that need addressing, and voids most manufacturer guarantees. We strip back to the deck on every flat roof we install — the small extra cost prevents enormous future problems." } }, { "@type": "Question", "name": "How quickly can a flat roof be installed?", "acceptedAnswer": { "@type": "Answer", "text": "A typical garage or single-storey extension flat roof is 2–3 days from arrival to completion in dry weather. Larger or more complex roofs (multiple upstands, glazing penetrations, balcony decks) run 4–7 days. Weather windows are the main scheduling variable." } }, { "@type": "Question", "name": "Will a flat roof leak in heavy rain?", "acceptedAnswer": { "@type": "Answer", "text": "A correctly installed flat roof with proper falls and trims handles UK rainfall without issue. Leaks come from inadequate falls (water ponding rather than draining), failed upstands, blocked outlets, or ageing seams on older felt roofs. We design every flat roof to drain properly." } }, { "@type": "Question", "name": "Do flat roofs need maintenance?", "acceptedAnswer": { "@type": "Answer", "text": "Annual inspection and clearing outlets is sensible — leaves and moss build-up restricting drainage is the most common cause of premature failure. Most flat roofs we install need essentially no other intervention for 15–20 years." } }, { "@type": "Question", "name": "Is the work guaranteed?", "acceptedAnswer": { "@type": "Answer", "text": "Yes. Two layers of guarantee — our completion sign-off on EPDM and GRP installations. Both are passed to you in writing on completion." } }, { "@type": "Question", "name": "Can you replace a flat roof in winter?", "acceptedAnswer": { "@type": "Answer", "text": "EPDM can be installed in cold weather provided it's dry and surfaces are above the bonding adhesive's minimum temperature. GRP needs warmer, drier conditions — usually March to October. We schedule around weather windows realistically, not optimistically." } } ] }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://jandco-contractorsltd.co.uk/" }, { "@type": "ListItem", "position": 2, "name": "Roofing", "item": "https://jandco-contractorsltd.co.uk/roofing/" }, { "@type": "ListItem", "position": 3, "name": "Flat Roofing", "item": "https://jandco-contractorsltd.co.uk/flat-roofing/" } ] }, { "@context": "https://schema.org", "@type": "Person", "name": "Jamie Pocock", "jobTitle": "Owner & Lead Contractor", "worksFor": { "@id": "https://jandco-contractorsltd.co.uk/#business" }, "knowsAbout": [ "Flat Roofing", "Roofing", "Building", "Construction" ] } ] --- We use essential cookies to run this site, and optional cookies only with your consent. [Cookie policy](/cookie-policy/) AcceptReject Open 7 days · Hours vary by day · 25 years' experience [Office: 01279 216 215](tel:01279216215) | [Mobile: 07379 964569](tel:07379964569) [![J&Co Contractors logo](/assets/jandco-logo-DkXiFtbE.png)](/) Services Areas [About](/about/) [Our Work](/our-work/) [Blog](/blog/) [Reviews](/reviews/) [Contact](/contact/) [01279 216 215](tel:01279216215) [Free Quote](/contact/) ![Newly installed black EPDM flat roof on a single-storey extension in Hertfordshire](/assets/wa-435-47-C__F_29U.jpeg) 1. [Home](/) 2. [Roofing](/roofing/) 3. Flat Roofing Flat Roofing # Flat Roofing Specialists in Bishop's Stortford & Hertfordshire EPDM rubber, GRP fibreglass and high-performance felt flat roofs installed properly the first time — built to last 25+ years on garages, dormers, single-storey extensions and outbuildings. [Get a Free Quote](/contact) [01279 216 215](tel:01279216215) 25 years' experience Five-star rated Workmanship guarantee 25 Years' Experience CRC Certified Roofer SafeContractor Approved Workmanship Guarantee Open 7 Days Herts & Essex Coverage Overview ## Modern Flat Roofs That Actually Last A flat roof done properly is one of the most reliable, low-maintenance coverings you can put on a UK property. A flat roof done badly is the most common source of leaks we get called to fix. The difference comes down to three things: the right system specified for the job, the deck preparation underneath it, and the detail at the upstands and trims. We install three flat roof systems regularly — EPDM rubber for most domestic projects, GRP fibreglass where rigidity and aesthetics matter, and modern torch-on felt where budget is the deciding factor. We'll specify what's right for your roof, not what makes us the easiest profit. ![Newly installed black EPDM rubber flat roof on a single-storey rear extension in Hertfordshire](/assets/wa-435-47-C__F_29U.jpeg) Why It Matters ## What Happens When a Flat Roof Goes Wrong An ageing or badly installed flat roof rarely fails at the surface — it fails at the joints, the upstands and the trims. Once water tracks underneath the membrane, it spreads sideways across the deck and emerges metres from the actual entry point, making diagnosis difficult and damage extensive. Common shortcuts we see: timber decks not properly fixed before the membrane goes down, drip edges omitted, upstands too low against adjoining brickwork, and felt overlaid on existing failed felt rather than fully stripped. Each of these turns a 25-year roof into a 5-year problem. Our [roof repair team](/roof-repairs/) sees the consequences every winter. Our Process ## How We Deliver Flat Roofing 01 ### Survey & Spec We inspect the existing roof and deck, identify any timber repairs needed, and recommend the right system for the application. 02 ### Strip & Prep Old covering fully stripped, deck inspected and replaced where needed, falls corrected, all fixings checked and tightened. 03 ### Membrane Install EPDM, GRP or felt installed to manufacturer specification with proper bonding, seam detail and drip edges. 04 ### Upstands & Trims Lead or proprietary trims dressed in, upstands sealed against adjoining walls, downpipe outlets fitted. 05 ### Sign-off & Guarantee Water test, final inspection. Benefits ## What You Get with J&Co ### 25+ Year Lifespan When properly specified and installed, EPDM and GRP systems routinely outlast their stated guarantees. ### Manufacturer Guarantee Approved installer guarantees passed directly to you on every system roof. ### Single-Piece Membrane Most domestic EPDM roofs installed as one continuous piece — no seams to fail. ### Proper Deck Prep Deck inspected, strengthened and corrected for fall before any membrane goes down. Technical Detail ## EPDM vs GRP vs Felt — Which Flat Roof System is Right? **EPDM rubber** is our most-specified domestic system. Single-piece membrane on most garage and extension roofs, no joints to leak, 25+ year manufacturer-backed lifespans, and reasonably forgiving on small movement in the deck. Cost-effective, fast to install, and the right answer for most flat roofs we quote. **GRP fibreglass** is rigid, seamless across the full roof, and arguably the best-looking option when the roof is visible from above. Slightly more expensive than EPDM, requires good weather conditions to install properly, but extremely durable and walkable. Often the right choice for balconies, dormers and high-spec extensions. **Modern torch-on felt** is the budget option. Three-layer high-performance felt systems still give 15–20 years when laid properly. We install it where budget is the deciding factor, but we'll always be straight about the trade-off in lifespan compared with EPDM. Whatever the system, the thing that decides whether a flat roof actually lasts is the prep underneath. We don't compromise on that. See also our [roof repair service](/roof-repairs/) for any existing flat roof issues. ![Close-up of EPDM rubber membrane and trim detail on a domestic flat roof](/assets/wa-435-47-C__F_29U.jpeg) EPDM single-piece membrane install on a Hertfordshire single-storey extension. Honest Pricing ## How Much Does a Flat Roof Cost in Hertfordshire? Honest guide ranges below — every roof is quoted individually after a free site survey. We don't do day rates and we don't do open-ended pricing. Garage flat roof (EPDM) £1,800–£3,200 Strip and re-cover of a typical single garage including new trims and outlet. Single-storey extension £2,500–£4,500 EPDM or GRP on a typical 4m × 5m extension including any deck repairs. Larger flat roof (>40m²) From £4,500 Full system roof including upstand detail, drip trims and downpipe outlets. ### What affects the price - Roof size and shape - System chosen (EPDM / GRP / felt) - Existing deck condition - Access and scaffold requirements - Number of upstands and penetrations - Insulation upgrades (if required) [Get Your Free Written Quote](/contact) Service Area ## Areas We Cover for Flat Roofing We deliver this service across our full Hertfordshire and Essex catchment. Regular projects in [Bishop's Stortford](/areas/bishops-stortford/), [Sawbridgeworth](/areas/sawbridgeworth/), [Harlow](/areas/harlow/), [Saffron Walden](/areas/saffron-walden/), Stansted Mountfitchet, Great Dunmow, Epping, Ware, Hoddesdon, Broxbourne, Cheshunt, Welwyn Garden City and Stevenage. Outside this list? Call us with your postcode — we frequently work the wider London fringe and across the rest of Hertfordshire. Guides ## Flat Roofing guides & cost advice Free, no-nonsense reading from Jamie on the questions we get asked most about flat roofing. - [EPDM vs GRP Flat Roofs: Which Is Better? EPDM rubber and GRP fibreglass are the two flat-roof systems we install most often. Both will outlast felt by decades — but they suit different roofs, budgets and access conditions. Here's the honest comparison. ](/guides/epdm-vs-grp-flat-roofs/) - [How Much Does a Flat Roof Cost in 2026? Flat roof prices vary widely by system, size, deck condition and access. Here are the honest 2026 figures we quote on real Hertfordshire and Essex jobs — including what's normally hidden in cheap quotes. ](/guides/how-much-does-a-flat-roof-cost/) FAQs ## Flat Roofing — Frequently Asked Questions ### How long does a new flat roof last? ### Can you install over the existing flat roof? ### How quickly can a flat roof be installed? ### Will a flat roof leak in heavy rain? ### Do flat roofs need maintenance? ### Is the work guaranteed? ### Can you replace a flat roof in winter? Related Services [Roof Repairs & Maintenance](/roof-repairs/) [Guttering, Fascias & Soffits](/guttering-fascias-soffits/) [Emergency Roof Repairs](/emergency-roof-repairs/) [Building & Extensions](/building-extensions/) [Back to Roofing](/roofing/) ## Get a Free Flat Roofing Quote Owner-led survey, written itemised quote, manufacturer-backed system guarantee. Across Hertfordshire and Essex, seven days a week. [Request Free Quote](/contact) [01279 216 215](tel:01279216215) Page last updated: May 2026 · J&Co Builders Ltd · 1 Ugley Hall Cottages, Bishop's Stortford CM22 6JB ![J&Co Contractors](/assets/jandco-logo-DkXiFtbE.png) Owner-led roofing and building contractors covering Bishop's Stortford, Hertfordshire and Essex. 25 years of hands-on trade experience. Open seven days. [01279 216 215 (office)](tel:01279216215) [07379 964569 (mobile)](tel:07379964569) [info@jandco-contractorsltd.co.uk](mailto:info@jandco-contractorsltd.co.uk) 1 Ugley Hall Cottages, Bishop's Stortford CM22 6JB Open 7 days a week - Sun 07:00–17:30 - Mon 07:00–17:00 - Tue 07:30–17:00 - Wed 07:00–17:30 - Thu 07:00–17:30 - Fri 06:00–18:00 - Sat 09:00–17:00 [](https://www.facebook.com/share/18mTGdCPdF/?mibextid=wwXIfr) ### Roofing - [All roofing services](/roofing/) - [Flat Roofing](/flat-roofing/) - [Roof Repairs & Maintenance](/roof-repairs/) - [Emergency Roof Repairs](/emergency-roof-repairs/) - [Guttering, Fascias & Soffits](/guttering-fascias-soffits/) - [Chimney Repairs & Repointing](/chimney-repairs-repointing/) ### Building & Construction - [All building services](/building-construction/) - [Building & Extensions](/building-extensions/) - [Loft Conversions](/loft-conversions/) - [Renovations & Refurbishments](/renovations-refurbishments/) - [Brickwork & Masonry](/brickwork-masonry/) - [Damp Proofing & Waterproofing](/damp-proofing-waterproofing/) - [Plastering & Rendering](/plastering-rendering/) - [Patio & Driveway Installations](/patio-driveway-installations/) - [Fencing & Garden Walls](/fencing-garden-walls/) - [Property Maintenance](/property-maintenance/) ### Areas We Cover - [Bishop's Stortford](/areas/bishops-stortford/) - [Stansted Mountfitchet](/areas/stansted-mountfitchet/) - [Sawbridgeworth](/areas/sawbridgeworth/) - [Great Dunmow](/areas/great-dunmow/) - [Harlow](/areas/harlow/) - [Saffron Walden](/areas/saffron-walden/) - [Epping](/areas/epping/) - [Ware](/areas/ware/) - [Hoddesdon](/areas/hoddesdon/) - [Broxbourne](/areas/broxbourne/) - [Cheshunt](/areas/cheshunt/) - [Welwyn Garden City](/areas/welwyn-garden-city/) - [Stevenage](/areas/stevenage/) ### Company - [About J&Co](/about/) - [Our Recent Work](/our-work/) - [Blog](/blog/) - [Customer Reviews](/reviews/) - [Contact Us](/contact/) © 2026 J&Co Builders Ltd · Trading as J&Co Contractors · All rights reserved. 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