07447 188036info@gnbroofing.co.uk Serving East AngliaMon–Sat 7am–6pm HomeAboutServicesFlat Roof InstallationFlat Roof ReplacementFlat Roof RepairsEPDM Rubber RoofingSingle-Ply Membrane (SFlex · Sika Plan · Resitrix)Commercial Flat RoofingFascias & Soffits (UPVC)Guttering & BargeboardsCladding — UPVC, Timber-Effect & Composite AreasNorfolk NorwichThorpe St Andrew & SprowstonHellesdonCostesseyTaverhamDraytonCringlefordWymondhamDerehamGreat YarmouthThetfordKing's Lynn County overview Norfolk (county overview)Suffolk (county overview)Cambridgeshire (county overview) Our WorkReviewsContact07447 188036Get Free Quote - Home - Services - Single-Ply Membrane (SFlex · Sika Plan · Resitrix) Single-Ply Membrane (SFlex · Sika Plan · Resitrix) # Single-Ply Membrane RoofingSFlex · Sika Plan · Resitrix Premium single-ply membrane systems — SFlex, Sika Plan and Resitrix — installed by a Sika Plan Approved contractor with the extended manufacturer warranty that comes with it. Get my free fixed-price quote 07447 188036 Free survey · No call-out fees · Written quote in 3–4 days · You deal with Neil directly Flat-roofing specialist Sika Plan Approved Installer 20-yr product / 10-yr workmanship PL & EL fully insured Free fixed-price quotes Service overview ## What we do, who it's for, and when to book it. ### What it is Design and installation of mechanically fixed and adhered single-ply membrane roofing systems on domestic extensions, larger residential roofs, and commercial buildings. ### Who it's for Homeowners with larger or complex flat roofs, architects and specifiers who need a warrantied premium system, and commercial owners who need a 30+ year design-life covering. ### When it's needed On new-build and full-replacement projects where a premium, manufacturer-warranted long-life covering is the goal — not a budget stop-gap. ### Why it matters Single-ply membranes have the longest track record of any modern flat roof product. Correctly installed, Sika Plan roofs have documented service lives well past 30 years. The catch: they must be installed by an approved contractor, or the warranty is void. The cost of leaving it ## What actually happens when this is put off. ### If it's ignored - Specifying a premium membrane but letting an unapproved installer fit it voids the manufacturer warranty — you paid for a Rolls-Royce and got the paperwork of a hire car. - Under-specified fixings or adhesive on an exposed roof can lift in a design-storm event, taking the roof edge with it. - Ignoring the vapour control layer under a warm-roof single-ply build-up traps interstitial condensation — invisible for years, then catastrophic. ### Common mistakes we clean up after - Choosing the cheapest quote for a spec that only pays off if it's installed correctly. - Skipping the manufacturer's system-warranty inspection because it 'costs extra' — it's how you get the 20+ year cover. - Mixing brands: a Sika membrane with a non-Sika insulation and a random adhesive is not a warrantied system. Our process ## A predictable path from first call to guaranteed sign-off. - 01 Free technical survey Deck check, exposure assessment, insulation strategy and system recommendation. - 02 Fixed written specification & quote Named membrane, insulation, VCL, fixings/adhesive, upstand and outlet detail, and price. - 03 Strip and substrate prep Existing covering removed, deck repaired, falls corrected if needed. - 04 Warm-roof build-up Vapour control layer, PIR insulation, then membrane installed to manufacturer specification. - 05 Detailing & manufacturer sign-off Upstands, terminations, outlets and flashings completed to spec; system warranty issued. What you actually get ## The outcomes — not the sales talk. Sika Plan Approved Installer Manufacturer stands behind our workmanship with an extended system warranty. 20-year product / 10-year workmanship In writing, in your name. Longest track record on the market Documented 30+ year service life on properly installed single-ply systems. Clean, uniform finish Ideal for visible roofs, terraces overlooked from higher storeys, and premium new-builds. Fixed price, no call-out fees Survey free, quote fixed. Owner-run job Neil is on the roof — not a subcontracted crew you've never met. Specification detail ## The technical honest version. Single-ply membrane is a category, not a product. Choosing between SFlex, Sika Plan and Resitrix depends on roof size, detailing complexity, budget and exposure. ### SFlex PVC single-ply Cost-effective PVC single-ply suited to larger domestic and mid-tier commercial. Mechanically fixed or adhered depending on deck and exposure. ### Sika Plan (Sarnafil family) Premium PVC single-ply with a documented 30+ year service life. Our Sika Plan Approved status unlocks the extended manufacturer system warranty. ### Resitrix self-adhesive EPDM Where the roof has heavy upstand and penetration detail, or where the existing substrate is bitumen, Resitrix is often the cleanest install. ### Mechanically fixed vs fully adhered Mechanical fixing is faster and better on high-exposure sites; fully adhered gives a cleaner visual finish on roofs overlooked from above. We spec case by case. ### Insulation and vapour control The membrane is only one layer of a five-layer warm-roof build-up. Get the VCL and insulation right and the membrane will do its job for decades. ### Residential vs commercial Same materials, different scale. Commercial jobs add phasing, edge-protection scaffolding, and often more penetration detailing — all priced in from day one, not billed as extras. Frequently asked ## Questions we answer at almost every survey. What is single-ply membrane roofing?+A single sheet of PVC or EPDM installed either mechanically fixed or fully adhered over insulation on a warm-roof build-up. It replaces multi-layer felt with a single, homogeneous covering. Why does the 'approved installer' status matter?+The manufacturer's extended warranty is only issued when the installer is trained and audited by them. Same material, different installer, different warranty. How long will a Sika Plan roof last?+Documented service lives of 30+ years are common on correctly installed Sika Plan roofs. Product warranty is 20 years. Can single-ply be used on residential?+Yes — increasingly the go-to for large or premium domestic roofs. It's not just a commercial system. Is it fire-rated?+The systems we install meet the relevant fire performance standards for their application. We'll confirm the specific rating for your project at survey. How is it fixed?+Either mechanically (fixings through the membrane into the deck at defined centres) or fully adhered (bonded across the full area). Choice depends on deck, exposure and finish requirements. Do you cover the whole of Norfolk, Suffolk & Cambridgeshire?+Yes. We're based in Norwich (NR5) and work across Norfolk, Suffolk and Cambridgeshire — including all the Norwich suburbs (Thorpe St Andrew, Sprowston, Hellesdon, Costessey, Taverham, Drayton, Cringleford), Wymondham, Dereham, Thetford, Great Yarmouth and King's Lynn. If you're on the edge of that area, phone and ask — we don't charge to travel to quote. Do you charge call-out fees?+No. Surveys and quotes are free, and there are no call-out fees. You get a fixed written price before any work starts — no day-rates, no hidden extras. Who will I actually deal with?+Neil, the owner, personally quotes and runs every job. You won't be handed to a call centre or a subcontracted crew. One point of contact from first call to final sign-off. Where we cover ## Single-Ply Membrane (SFlex · Sika Plan · Resitrix) across Norfolk, Suffolk & Cambridgeshire. NorwichThorpe St Andrew & SprowstonHellesdonCostesseyTaverhamDraytonCringlefordWymondhamDerehamGreat YarmouthThetfordKing's LynnNorfolk (county overview)Suffolk (county overview)Cambridgeshire (county overview) Related services ## Also worth looking at. Flat Roof Installation A properly specified, single-ply or EPDM flat roof — installed by a Sika Plan Approved Installer, guaranteed 20 years on materials and 10 years on workmanship, for a fixed written price with zero call-out fees. View service Commercial Flat Roofing Warrantied, long-life commercial flat roofing — installed by a Sika Plan Approved contractor, scheduled around your operations, priced fixed with no day-rate creep. View service EPDM Rubber Roofing A one-piece EPDM rubber roof — seamless, low-maintenance, 25+ year design life — installed for a fixed written price by an owner-run, insured, Sika Plan Approved installer. View service One next step ## Get a fixed written quote for your single-ply membrane (sflex · sika plan · resitrix) — in 3–4 days. Free survey. No call-out fees. Sika Plan Approved. 20-year product / 10-year workmanship guarantee. Neil quotes it and Neil installs it. Book my free survey Call 07447 188036 Mon–Sat 7am–6pm Flat-roofing specialists serving homes and businesses across East Anglia. Sika Plan Approved. Fully insured. Owner-run by Neil Cockman. Sika Plan Approved Installer ### Services - Flat Roof Installation - Flat Roof Replacement - Flat Roof Repairs - EPDM Rubber Roofing - Single-Ply Membrane - Commercial Flat Roofing - Fascias & Soffits ### Service Areas - Norwich - Thorpe St Andrew & Sprowston - Hellesdon - Costessey - Taverham - Drayton - Cringleford - Wymondham - Dereham - Great Yarmouth - Thetford - King's Lynn - Norfolk (county overview) - Suffolk (county overview) - Cambridgeshire (county overview) ### Contact - 07447 188036 - info@gnbroofing.co.uk - 6 Gilbard RoadNorwich, NR5 8TR - Mon–Sat 7am–6pm · Closed Sun © 2026 GNB Roofing Services. All rights reserved.Privacy PolicyCookie PolicyTerms & Conditions Call NowGet Free Quote We use essential cookies to make this site work, and optional ones only if you accept. Cookie policy. AcceptReject