{"product_id":"ariston-black-vent-cap-base-for-flat-roof-coaxial-vertical-flue-flashing","title":"Ariston Black Vent Cap Base For Flat Roof – Coaxial Vertical Flue Flashing","description":"\u003cdiv style=\"font-size: 16px; font-family: Arial,sans-serif; color: #222; max-width: 900px; margin: 0 auto; line-height: 1.6;\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eAriston Black Vent Cap Base for Flat Roof (Part No. 3318011)\u003c\/strong\u003e is the \u003cstrong\u003egenuine Ariston weatherproofing flashing plate\u003c\/strong\u003e used when a vertical coaxial flue passes through a flat or low-pitch roof. It creates a \u003cstrong\u003efully watertight seal around the flue pipe penetration\u003c\/strong\u003e, preventing rainwater ingress at the roof surface — a critical detail on any vertical flue installation where the terminal exits through a flat roof rather than a pitched surface with a conventional angled flashing. Compatible with all \u003cstrong\u003eAriston HE condensing boilers\u003c\/strong\u003e using the \u003cstrong\u003estandard Ø60\/100 and Ø80\/125 coaxial vertical flue systems\u003c\/strong\u003e, it pairs with the \u003cstrong\u003eVertical Starter (3318079)\u003c\/strong\u003e and the \u003cstrong\u003eVertical Flue Kit (3318080, 3318081, or 3319235)\u003c\/strong\u003e to complete a code-compliant vertical flue installation. \u003cstrong\u003eNot included with any flue kit\u003c\/strong\u003e — this must be ordered separately whenever a flat-roof termination is required.\u003c\/p\u003e\n\u003cdiv style=\"display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0;\"\u003e\n\u003cdiv style=\"background: #008377CF; color: #fff; border-radius: 8px; padding: 14px 18px; flex: 1 1 150px; text-align: center;\"\u003e\n\u003cdiv style=\"font-size: 18px; font-weight: bold;\"\u003eFlat Roof\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; margin-top: 4px;\"\u003eApplication\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background: #008377CF; color: #fff; border-radius: 8px; padding: 14px 18px; flex: 1 1 150px; text-align: center;\"\u003e\n\u003cdiv style=\"font-size: 18px; font-weight: bold;\"\u003eØ60\/100\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; margin-top: 4px;\"\u003eCoaxial System — Standard HE\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background: #008377CF; color: #fff; border-radius: 8px; padding: 14px 18px; flex: 1 1 150px; text-align: center;\"\u003e\n\u003cdiv style=\"font-size: 18px; font-weight: bold;\"\u003eØ80\/125\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; margin-top: 4px;\"\u003eCoaxial System — Extended\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background: #008377CF; color: #fff; border-radius: 8px; padding: 14px 18px; flex: 1 1 150px; text-align: center;\"\u003e\n\u003cdiv style=\"font-size: 18px; font-weight: bold;\"\u003eBlack\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; margin-top: 4px;\"\u003eFinish\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background: #fdecea; border-left: 4px solid #c0392b; padding: 14px 16px; border-radius: 6px; margin: 18px 0;\"\u003e\n\u003cstrong\u003e⚠ Must Be Fitted Before the Flue Terminal Is Installed:\u003c\/strong\u003e The vent cap base must be positioned and secured to the roof surface \u003cstrong\u003ebefore\u003c\/strong\u003e the vertical flue terminal is pushed through and seated. Attempting to retrofit the flashing plate after the flue kit is in place is not possible without dismantling the flue assembly. Always plan the flashing installation sequence before committing to roof cuts.\u003c\/div\u003e\n\u003cdiv style=\"background: #fff3cd; border-left: 4px solid #e6a817; padding: 14px 16px; border-radius: 6px; margin: 18px 0;\"\u003e\n\u003cstrong\u003e⚠ For Flat Roofs Only — Not Suitable for Pitched Roofs:\u003c\/strong\u003e The 3318011 is designed for use on \u003cstrong\u003eflat or near-flat roof surfaces (0–10° pitch)\u003c\/strong\u003e. For pitched roofs, use the \u003cstrong\u003eAriston Flexible Base Cap Flashings — Part No. 3318009 (black, 12–40°) or 3318010 (red, 12–40°)\u003c\/strong\u003e. Using a flat-roof base cap on a sloping surface will not create an adequate weatherproof seal and risks water ingress.\u003c\/div\u003e\n\u003cdiv style=\"background: #e6f4f3; border-left: 4px solid #008377; padding: 14px 16px; border-radius: 6px; margin: 18px 0;\"\u003e\n\u003cstrong\u003eℹ Note on 100mm Terminal Compatibility (3319235):\u003c\/strong\u003e The 3318011 is sized for the \u003cstrong\u003estandard Ariston domestic 125mm terminal\u003c\/strong\u003e used by the 3318080 and 3318081 vertical flue kits. If you are installing the \u003cstrong\u003e3319235 leisure\/caravan 100mm terminal\u003c\/strong\u003e, this flashing is \u003cstrong\u003eunlikely to provide a correct seal\u003c\/strong\u003e around the smaller terminal — a 100mm-rated cowl or flashing specific to the leisure sector should be sourced instead.\u003c\/div\u003e\n\u003cdiv style=\"display: grid; grid-template-columns: repeat(auto-fill,minmax(250px,1fr)); gap: 16px; margin: 24px 0;\"\u003e\n\u003cdiv style=\"border: 1px solid #ddd; border-radius: 8px; padding: 16px;\"\u003e\n\u003cdiv style=\"font-size: 16px; font-weight: bold; border-bottom: 2px solid #008377; padding-bottom: 6px; margin-bottom: 10px;\"\u003eWatertight Flat Roof Seal\u003c\/div\u003e\n\u003cp style=\"margin: 0; font-size: 15px;\"\u003eThe 3318011 is engineered to form a \u003cstrong\u003eweatherproof seal at the point where the coaxial flue pipe passes through a flat roof\u003c\/strong\u003e. Without a properly fitted flashing, the annular gap between the pipe and the roof aperture provides a direct water ingress path — a latent defect that may not become apparent until the first significant rainfall after commissioning.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #ddd; border-radius: 8px; padding: 16px;\"\u003e\n\u003cdiv style=\"font-size: 16px; font-weight: bold; border-bottom: 2px solid #008377; padding-bottom: 6px; margin-bottom: 10px;\"\u003eGenuine Ariston Part — Assured Compatibility\u003c\/div\u003e\n\u003cp style=\"margin: 0; font-size: 15px;\"\u003eAs a \u003cstrong\u003egenuine Ariston accessory\u003c\/strong\u003e, the 3318011 is dimensioned and tested to work with Ariston's coaxial flue pipe outer diameter and terminal geometry. Third-party flat-roof flashings vary in internal aperture and sealing design — using a non-genuine flashing risks poor fitment and inadequate waterproofing, which would affect both Building Regulations compliance and warranty validity.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #ddd; border-radius: 8px; padding: 16px;\"\u003e\n\u003cdiv style=\"font-size: 16px; font-weight: bold; border-bottom: 2px solid #008377; padding-bottom: 6px; margin-bottom: 10px;\"\u003eDual Flue System Compatibility\u003c\/div\u003e\n\u003cp style=\"margin: 0; font-size: 15px;\"\u003eThe 3318011 is compatible with both the \u003cstrong\u003estandard Ø60\/100 coaxial system\u003c\/strong\u003e (used by E-Combi ONE, Clas ONE, Genus ONE, Alteas ONE) and the \u003cstrong\u003elarger Ø80\/125 coaxial system\u003c\/strong\u003e used on higher-output boilers or longer flue runs. This makes it a single stocking item suitable across most of the Ariston HE condensing range.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"overflow-x: auto; margin: 24px 0;\"\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 15px;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background: #008377CF; color: #fff;\"\u003e\n\u003cth colspan=\"2\" style=\"padding: 10px 12px; text-align: left;\"\u003eSpecifications — Ariston Black Vent Cap Base for Flat Roof\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e3318011\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eColour\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eApplication\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003eFlat roof vertical flue termination weatherproofing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eSuitable Roof Pitch\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003eFlat \/ near-flat (0–10°)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eCompatible Flue Diameter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003eØ60\/100 mm and Ø80\/125 mm coaxial (125mm terminal — domestic kits)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eCompatible Boiler Ranges\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003eAll Ariston HE condensing boilers — E-Combi ONE, Clas ONE, Genus ONE, Alteas ONE, Alteas ONE+ NET and equivalent ranges\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eUsed With\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003eVertical Starter 3318079 + Vertical Flue Kit 3318080 (black) or 3318081 (red)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eNot Compatible With\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e3319235 leisure\/caravan 100mm terminal — use a 100mm-rated leisure cowl instead\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e\u003cstrong\u003eAlternative for Pitched Roofs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #e0e0e0;\"\u003e3318009 (flexible base cap, black, 12–40°) \/ 3318010 (flexible base cap, red, 12–40°)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px;\"\u003e\u003cstrong\u003eIncluded in Flue Kits\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px;\"\u003eNo — must be ordered separately for all flat-roof vertical flue installations\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin: 28px 0;\"\u003e\n\u003cdiv style=\"background: #008377CF; color: #fff; padding: 12px 16px; border-radius: 6px 6px 0 0; font-weight: bold; font-size: 16px;\"\u003eFrequently Asked Questions\u003c\/div\u003e\n\u003cdetails style=\"border: 1px solid #ddd; border-top: none; padding: 0;\"\u003e\n\u003csummary style=\"padding: 14px 16px; cursor: pointer; font-weight: 600; background: #f9f9f9;\"\u003eIs the vent cap base included with the vertical flue kit?\u003c\/summary\u003e\n\u003cdiv style=\"padding: 14px 16px; border-top: 1px solid #eee;\"\u003eNo. Neither the standard Ariston vertical flue kits (3318080, 3318081) nor the leisure 100mm kit (3319235) include a roof flashing. The \u003cstrong\u003e3318011 must always be ordered separately\u003c\/strong\u003e for any flat-roof vertical flue installation. It is also not included with the Vertical Starter (3318079). Plan for this component at the quotation stage to avoid a delay during installation.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails style=\"border: 1px solid #ddd; border-top: none; padding: 0;\"\u003e\n\u003csummary style=\"padding: 14px 16px; cursor: pointer; font-weight: 600; background: #f9f9f9;\"\u003eCan I use the 3318011 with the leisure 100mm flue kit (3319235)?\u003c\/summary\u003e\n\u003cdiv style=\"padding: 14px 16px; border-top: 1px solid #eee;\"\u003eThe 3318011 is sized for the \u003cstrong\u003e125mm terminal\u003c\/strong\u003e used on standard domestic Ariston vertical flue kits. The \u003cstrong\u003e3319235 uses a smaller 100mm terminal\u003c\/strong\u003e, so the 3318011 will not form a correct weatherproof seal around it. For leisure installations using the 3319235, source a \u003cstrong\u003e100mm cowl or flashing rated for that terminal diameter\u003c\/strong\u003e from a leisure\/caravan heating specialist instead.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails style=\"border: 1px solid #ddd; border-top: none; padding: 0;\"\u003e\n\u003csummary style=\"padding: 14px 16px; cursor: pointer; font-weight: 600; background: #f9f9f9;\"\u003eWhat is the installation sequence for a flat-roof vertical flue?\u003c\/summary\u003e\n\u003cdiv style=\"padding: 14px 16px; border-top: 1px solid #eee;\"\u003eThe correct sequence is: (1) fit and commission the boiler; (2) cut the \u003cstrong\u003e130mm diameter hole\u003c\/strong\u003e through the ceiling and roof; (3) \u003cstrong\u003efit and seal the 3318011 flashing plate to the roof surface\u003c\/strong\u003e with appropriate sealant for your roof membrane type; (4) fit the Vertical Starter (3318079) to the boiler manifold; (5) pass the vertical flue kit up through the ceiling and roof aperture; (6) push the flue kit into the starter and confirm all push-fit seals are fully engaged. Do not skip step 3 — the flashing must be in place before the terminal is seated through it.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails style=\"border: 1px solid #ddd; border-top: none; padding: 0;\"\u003e\n\u003csummary style=\"padding: 14px 16px; cursor: pointer; font-weight: 600; background: #f9f9f9;\"\u003eWhat if my roof has a slight pitch — can I still use the 3318011?\u003c\/summary\u003e\n\u003cdiv style=\"padding: 14px 16px; border-top: 1px solid #eee;\"\u003eThe 3318011 is intended for \u003cstrong\u003eflat or near-flat roof applications up to approximately 10°\u003c\/strong\u003e. Beyond that, the flat base plate will not sit flush against the roof surface and the seal will be compromised. For pitched roofs between 12° and 40°, use the \u003cstrong\u003eAriston flexible base cap flashing — Part No. 3318009 (black) or 3318010 (red)\u003c\/strong\u003e, which conform to the roof surface across that pitch range.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Ariston","offers":[{"title":"Default Title","offer_id":64898805432669,"sku":"3318011","price":33.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/ariston-black-flat-roof-base-cap-3318011.jpg?v=1780588083","url":"https:\/\/qualityheating.co.uk\/products\/ariston-black-vent-cap-base-for-flat-roof-coaxial-vertical-flue-flashing","provider":"AIZO Quality Heating","version":"1.0","type":"link"}