TR19 & standards
Those neat little doors in your ductwork aren't vandalism. They're the only way to clean and prove the parts of the system you never see.
The short answer
Kitchen extract ductwork runs above ceilings, up risers and through roof voids - out of sight and out of reach. TR19 Grease expects the whole system cleaned and measured, so access panels are cut in at intervals to reach it. Without them, sections stay uncleaned and unproven, which is a fire risk and a compliance gap, not a saving.
Why the holes have to be there
The grease that matters most is the grease nobody can see - lining a vertical riser, sitting in a duct run above a false ceiling, coating the blades of the extract fan. None of it can be inspected, cleaned or measured through a canopy opening. The only way in is a purpose-made access panel cut into the ductwork itself.
That is why a technician arriving at an older system often has to fit new panels before they can even start. It looks dramatic - cutting into ductwork - but a sealed, properly made access door is a permanent asset: it lets every future clean reach the same sections and lets readings be taken to prove the result. A system designed without access is the real problem; the panels are the fix.
What a compliant panel looks like
TR19 Grease and the related ductwork standards set out how access should be provided. Panels are positioned so all of the ductwork can be reached - as a rule of thumb roughly every 2 metres along the run, and never more than about 0.5 metres from the item being cleaned. They should sit on the side of the duct where possible; top or underside only as a last resort, and then sealed carefully so grease can't leak out.
Construction matters as much as position. A panel should be the same material as the duct, fitted with quick-release catches and a sealing gasket, and match the duct's fire rating - all in line with BS EN 12097 for access provision and BESA's DW/144 for the doors themselves. Vertical risers get openings at the bottom and top, and at each accessible floor, so the whole height can be cleaned.
The limit
Fitting panels does not clean anything on its own - it makes the clean possible. But without them, the honest outcome is a partial clean, with the unreachable sections logged as inaccessible on the report. That is the quiet difference between a certificate that covers your whole system and one that covers only the bits a cleaner could get to. If your ductwork has never had access designed in, adding it is usually the first, and most cost-effective, step to genuine compliance.
Questions
Because kitchen extract is largely concealed - above ceilings, in risers, through voids. Access panels are the only way to reach, clean and measure those sections. On older systems without access, fitting panels is a necessary first step.
As a guide, roughly every 2 metres along the ductwork and within about 0.5 metres of the item being cleaned, positioned so the whole system can be reached. Risers need openings at the bottom, top and each accessible floor.
No, when done correctly. A compliant panel matches the duct material and fire rating, seals with a gasket and quick-release catches, and leaves no sharp edges - all per BS EN 12097 and BESA DW/144. It becomes a permanent, reusable access point.
On the side where possible, as that seals best against grease leakage. Top or underside is a last resort and must be sealed carefully. The aim is reach to every section, not convenience.
Then those sections can't be cleaned or verified, and the report records a partial clean. Retrofitting access panels is usually straightforward and is what allows a full, compliant clean and certificate.
Phoenix Duct Clean · by the numbers
We survey access first, tell you where panels are missing, and fit compliant, sealed access doors so the whole run can be cleaned and certified.