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Kitchen extraction cleaning - access panels
Your kitchen extract ductwork can only be cleaned where it can be reached - and that means access panels. The TR19 Grease standard expects enough of them, placed so the whole system can be inspected and cleaned. Too few, and parts of your duct go uncleaned - a real fire risk. Here is how many access panels your ductwork should have, and why. This is general information, not a substitute for the current TR19 Grease specification or a competent survey.
The short answer
Kitchen extract ductwork accumulates grease on its internal surfaces, and that grease is a fire risk - so it has to be cleaned. But ductwork can only be cleaned where it can be physically reached, which (for enclosed ductwork) means through access panels (access doors/hatches cut into the duct). So the number and placement of access panels directly determines how much of the duct can actually be cleaned. The standard: TR19 Grease (the Building Engineering Services Association's specification for the fire-risk management, inspection and cleaning of kitchen extract systems) sets the expectation. It requires sufficient access to allow the whole system to be inspected and cleaned - access panels provided at intervals and positions such that every part of the ductwork can be reached. As a working guide (the exact requirements are in the current TR19 Grease specification), this typically means: access panels at regular intervals along straight runs (commonly cited as around every 2 metres), and additionally at every bend and change of direction (where grease collects and cleaning tools cannot pass), at each fan and item of plant, and either side of any component (a fire damper, an in-line fan) that cannot be cleaned through. So how many access panels your ductwork should have depends on its specific length, layout, number of bends and components - a long, complex, bendy duct needs many; a short, simple run needs fewer - but the principle is constant: enough, well placed, that no part of the duct is left unreachable. Why it matters: if there are too few access panels, parts of the duct cannot be reached, so they cannot be cleaned - and uncleaned duct accumulates grease, a fire risk, and means the system is not fully cleaned or compliant. So access panel provision is not a detail but the thing that makes the whole duct cleanable. A survey to the current TR19 Grease specification determines exactly how many your system needs and where. So your duct should have enough access panels, well placed, that the whole system can be cleaned - roughly every 2 metres and at every bend and fan, per TR19 Grease. This is general information, not a substitute for the current TR19 Grease specification or a competent survey.
Key points
Why access panels matter
The fundamental point is simple: kitchen extract ductwork can only be cleaned where it can be physically reached - and for enclosed ductwork, that means through access panels. The grease that builds up inside extract ductwork is on the internal surfaces, often along runs of enclosed duct that you cannot get to from outside. To clean it, a cleaner has to be able to reach those internal surfaces - which means openings into the duct: access panels (access doors or hatches) cut into the ductwork at intervals, through which the internal surfaces can be inspected and cleaned. Without an access panel, a section of enclosed duct simply cannot be reached, so it cannot be cleaned.
So the access panels are what make the duct cleanable - and their number and placement directly determine how much of the duct can actually be cleaned. A duct with plenty of well-placed access panels can be cleaned throughout; a duct with too few leaves sections unreachable and therefore uncleaned. This makes access panel provision not a minor detail but the thing that governs whether the whole system can be properly cleaned. It is why cleaners assess (and sometimes have to add) access panels, and why the standard sets expectations for them. So the reason access panels matter is that you can only clean what you can reach - and access panels are how you reach the inside of enclosed ductwork. The following sections cover what the TR19 Grease standard expects, how many that means, and why too few is a problem. So you can only clean what you can reach - hence access panels. This is general information.
What TR19 Grease expects
The recognised standard for kitchen extract cleaning - TR19 Grease - sets the expectation for access: enough access panels, well placed, that the whole system can be inspected and cleaned. TR19 Grease is the Building Engineering Services Association (BESA) specification for the fire-risk management, inspection and cleaning of kitchen extract systems - the standard the industry and insurers refer to. On access, its principle is that there must be sufficient access to enable the entire ductwork system to be inspected and cleaned - meaning access panels provided at intervals and in positions such that every part of the ductwork can be reached, inspected and cleaned. So the standard's requirement is coverage: no part of the system left unreachable.
This is a functional requirement (access sufficient to clean the whole system) rather than an arbitrary number - the number of access panels needed follows from the duct's length, layout and features. But TR19 Grease gives guidance on the intervals and positions to achieve that coverage (the specifics are in the current specification), which translate into a practical rule of thumb (the next section). The key point is that the standard expects the whole system to be accessible for cleaning - so a system that meets TR19 Grease has enough access panels, well placed, that all of it can be cleaned, while a system with too few does not meet the standard (part of it cannot be cleaned). So what TR19 Grease expects is access to inspect and clean the whole system - the basis for how many access panels your duct should have. So the standard expects access to the whole system. So TR19 Grease expects whole-system access. This is general information, not a substitute for the current specification.
How many, and where
Translating the standard into practice, the access panels your duct should have come down to regular intervals along the runs plus panels at the key features - as a working guide, roughly every 2 metres, and at every bend, fan and un-cleanable component. Along straight runs: access panels at regular intervals so the runs can be cleaned throughout - commonly cited as around every 2 metres (the exact interval per the current TR19 Grease specification and the cleaning method), because cleaning tools and access reach only so far along a duct from each opening. So a long straight run needs several panels along its length.
At the key features: additionally, access is needed at every bend and change of direction (bends collect grease and block the passage of cleaning tools, so each needs access to clean through and around it); at each fan and item of plant (to clean the fan and the duct either side); and either side of any component that cannot be cleaned through (a fire damper, an in-line fan, or similar - access both sides so the duct up to it can be cleaned). So the placement follows the duct's features, not just its length. How many in total therefore depends on your specific ductwork - its length, its number of bends and components, its layout: a long, complex, bendy duct needs many access panels; a short, simple straight run needs few. There is no single number - it is however many it takes, at these intervals and positions, to make the whole system cleanable. A competent survey to the current TR19 Grease specification determines exactly how many yours needs and where. So how many and where: regular intervals plus bends, fans and components. So intervals, bends, fans and components determine how many. This is general information, not a substitute for a competent survey.
Why too few is a problem
The reason access panel provision matters so much is that too few panels means parts of the duct cannot be reached - and unreachable duct goes uncleaned, accumulating grease and fire risk. If there are not enough access panels, or they are poorly placed, sections of the ductwork (a long run between distant panels, the far side of a bend, a stretch beyond a component) cannot be reached by the cleaner - so those sections are not cleaned. The grease on their internal surfaces stays and continues to build up.
This matters because that uncleaned grease is exactly the fire risk the cleaning exists to control: grease build-up in extract ductwork is combustible and a recognised cause of serious kitchen fires, and it does not matter that most of the duct was cleaned if a section was left with a heavy grease build-up - the fire risk remains in that section. So too few access panels means the system is not fully cleaned, the fire risk is not fully controlled, and the system does not meet the standard (which requires the whole system to be cleanable and cleaned). It also means the logbook and certificate should honestly reflect that parts could not be accessed - flagging the gap. This is why, when access is insufficient, cleaners recommend adding access panels (retrofitting them - as covered in the cost of retrofitting access panels): so the whole system can be reached and cleaned, closing the uncleaned-grease fire risk. So too few access panels is a real problem - unreachable duct goes uncleaned, leaving grease and fire risk. So unreachable duct goes uncleaned. This is general information.
Enough to clean it all
So how many access panels your ductwork should have comes down to this: enough, well placed, that the whole system can be inspected and cleaned - which the TR19 Grease standard expects. As a working guide, that means access at regular intervals along the runs (commonly around every 2 metres), plus at every bend, at each fan, and either side of any component that cannot be cleaned through - the exact number depending on your duct's length, layout and features, and determined by a competent survey to the current specification. The principle is constant: no part of the duct left unreachable and therefore uncleaned. So your duct should have enough access panels to clean it all.
This connects to what a proper, TR19-compliant extraction clean actually requires - and why access is assessed as part of it. A genuine extraction clean cleans the whole system (canopy, filters, and the ductwork throughout) to remove the grease that is the fire risk - and that is only possible if the whole system can be reached, which depends on adequate access panels. So a competent extraction cleaner assesses the access, cleans everything that can be reached, and - where access is insufficient - identifies where access panels are needed so the whole system can be cleaned (and reflects any inaccessible areas honestly in the report). So access panel provision is integral to a proper extraction clean and to genuine compliance: without enough access, the duct cannot be fully cleaned, so the fire risk is not fully controlled. Getting the access right - enough panels, well placed - is what makes the whole duct cleanable, and therefore what makes a full, compliant clean possible. So enough access panels make the whole duct cleanable. This is general information, not a substitute for the current TR19 Grease specification or a competent survey.
Questions
Because kitchen extract ductwork can only be cleaned where it can be physically reached, and for enclosed ductwork that means through access panels. The grease that builds up inside extract ductwork is on the internal surfaces, often along runs of enclosed duct you cannot reach from outside. To clean it, the cleaner has to reach those internal surfaces - which means openings into the duct: access panels (access doors or hatches) at intervals, through which the internal surfaces are inspected and cleaned. Without an access panel, a section of enclosed duct cannot be reached, so it cannot be cleaned - and the grease there stays and keeps building up. So the access panels are what make the duct cleanable, and their number and placement determine how much of the duct can actually be cleaned: plenty of well-placed panels mean the whole duct can be cleaned; too few leave sections unreachable and uncleaned. So your ductwork needs access panels because you can only clean what you can reach, and access panels are how you reach the inside of enclosed ductwork. This is general information.
TR19 Grease requires enough access panels, well placed, that the whole system can be inspected and cleaned - a functional requirement rather than a single fixed number. TR19 Grease (the BESA specification for kitchen extract fire-risk management, inspection and cleaning) requires sufficient access to enable the entire ductwork system to be inspected and cleaned - access panels provided at intervals and positions such that every part of the ductwork can be reached. As a working guide (the specifics are in the current specification), this typically means access at regular intervals along straight runs (commonly cited as around every 2 metres), plus at every bend and change of direction, at each fan and item of plant, and either side of any component that cannot be cleaned through. So the number needed follows from your duct's length, layout, bends and components - a long, complex duct needs many, a short simple run needs few. There is no single universal number; it is however many it takes to make the whole system cleanable. A competent survey to the current TR19 Grease specification determines exactly how many yours needs and where. So TR19 Grease requires enough for whole-system access. This is general information, not a substitute for the current specification.
At regular intervals along the runs, and additionally at every bend, at each fan, and either side of any component that cannot be cleaned through. Along straight runs: at regular intervals (commonly around every 2 metres, per the current specification and cleaning method) so the runs can be cleaned throughout, because access and cleaning tools reach only so far from each opening. At bends and changes of direction: because bends collect grease and block the passage of cleaning tools, each needs access to clean through and around it. At fans and plant: to clean the fan and the duct either side. Either side of un-cleanable components: a fire damper, an in-line fan or similar that cannot be cleaned through needs access both sides, so the duct up to it can be cleaned. So placement follows the duct's features (bends, fans, components) as well as its length - the panels positioned so that, between them, the whole system can be reached. A competent survey determines the exact positions for your ductwork. So access panels go at intervals plus at bends, fans and un-cleanable components. This is general information, not a substitute for a competent survey.
Parts of the duct cannot be reached, so they cannot be cleaned - leaving grease build-up and fire risk, and meaning the system is not fully cleaned or compliant. If there are too few access panels, or they are poorly placed, sections of the ductwork (a long run between distant panels, the far side of a bend, a stretch beyond a component) cannot be reached by the cleaner, so they are not cleaned - and the grease on their internal surfaces stays and keeps building up. That uncleaned grease is exactly the fire risk the cleaning exists to control (grease build-up in extract ductwork is combustible and a recognised cause of serious kitchen fires) - and it does not matter that most of the duct was cleaned if a section was left with heavy grease, because the fire risk remains there. So too few access panels means the system is not fully cleaned, the fire risk is not fully controlled, and the system does not meet the standard (which requires the whole system to be cleanable and cleaned). It should also be reflected honestly in the logbook (flagging the inaccessible areas). This is why, when access is insufficient, cleaners recommend adding access panels. So too few panels leaves uncleaned grease and fire risk. This is general information.
Yes - where existing ductwork has too few access panels, additional ones can be retrofitted (cut into the duct) so the whole system can be reached and cleaned. Many older or poorly-designed systems were installed with insufficient access, so parts cannot be cleaned - and the solution is to add access panels: cutting properly-made access doors/hatches into the ductwork at the intervals and positions needed (at bends, along long runs, at components) so the previously unreachable sections can be inspected and cleaned. This is a common and worthwhile step (retrofitting access panels), because it makes the whole system cleanable and closes the uncleaned-grease fire risk in the previously inaccessible sections. There is a cost to retrofitting access panels (as covered in the cost of retrofitting access panels), but it is what enables the system to be fully cleaned and compliant going forward. The panels should be proper, purpose-made access panels (correctly fitted and sealed), not just holes. So yes - access panels can and often should be added to existing ductwork with insufficient access, so it can all be cleaned. This is general information, not a substitute for a competent survey.
Adequate access is what makes a full, compliant clean possible - because the whole system can only be cleaned if it can all be reached. A genuine, TR19-compliant extraction clean cleans the whole system (canopy, filters and the ductwork throughout) to remove the grease that is the fire risk - and that is only possible if the whole system can be reached, which depends on adequate access panels. So a competent extraction cleaner assesses the access as part of the job: cleans everything that can be reached, and - where access is insufficient - identifies where access panels are needed so the whole system can be cleaned, reflecting any inaccessible areas honestly in the report. Without enough access, the duct cannot be fully cleaned, so the fire risk is not fully controlled and the clean is not fully compliant (the report should flag the gap). So access panel provision is integral to a proper, compliant extraction clean: getting the access right (enough panels, well placed) is what makes the whole duct cleanable and a full, compliant clean possible. So adequate access panels are essential to a compliant clean. This is general information, not a substitute for the current TR19 Grease specification.
Ductwork can only be cleaned where it can be reached, so the whole system needs adequate access panels. Our extraction cleaning assesses your access, cleans everything reachable to TR19 Grease, and identifies where access panels are needed to clean it all. Ask us to survey your access and clean your system properly.
