Process & access
A proper kitchen extract clean is a four-stage job - survey, access, clean, then certify. Skip a stage and the clean is not compliant, whatever the canopy looks like afterwards.
The short answer
People often picture duct cleaning as a single task - someone turns up, cleans, leaves. Under TR19 Grease it is really four connected stages: a survey that measures what is there and finds the access, the provision of access so the whole system can be reached, the clean itself down to bare metal, and the verification and certification that prove it was done. Each stage feeds the next. A clean with no survey is a guess; a clean with no access is partial; a clean with no verification has no proof. Understanding the four stages is the clearest way to tell a real clean from a canopy wipe.
Stage one and two
The survey comes first because you cannot clean what you have not assessed. A technician inspects the canopy, filters, ductwork, risers and fan, and measures the grease - in microns - using a Wet Film Thickness Test for soft grease or a Deposit Thickness Test for harder, carbonised deposits. That tells you how heavy the load is, where it is worst, and crucially whether the system can actually be reached. TR19 Grease sets a mean trigger of 200 microns for a whole-duct clean and calls for immediate spot cleaning where any point reaches 500 microns or more.
Access is stage two, and it is where many jobs quietly fall down. Kitchen ductwork hides above ceilings, in risers and across roofs, and it can only be cleaned where there are panels to open. TR19 Grease calls for access panels at a minimum of every two metres and at strategic points, so the whole run can be entered. Where panels are missing, the honest answer is to fit compliant ones before cleaning - because a length of duct with no way in is a length nobody can clean.
Stage three and four
The clean itself works the system back to bare metal. Chemical degreasers soften the deposits, hand scraping and brushing lift the heavy build-up, and rotary brush machines with long-reach cables clean the runs and risers, with everything captured under negative pressure into HEPA-filtered vacuums. The aim is a defined standard, not a judgement call: surfaces cleaned to below fifty microns of residual grease.
Then comes certification, which is what turns a clean into compliance. The surfaces are verified visually and by measurement to confirm they are under fifty microns, and a post-clean verification report is produced with before-and-after photographs taken from the same positions and the deposit readings recorded. The clean is registered - typically on the BESCA VHE portal, generating a certificate - and lodged on a national register that an insurer or fire risk assessor can check. Only when stage four is complete do you have a clean you can actually prove.
Why the order matters
The four stages are not a menu to pick from - they are a chain. A weak survey leads to a mis-scoped clean; missing access leaves untouched duct; a clean with no verification cannot be defended to an insurer. Run in order, they turn a greasy, hidden system into a documented, compliant one. That is the difference between a job that reads well on an invoice and one that holds up after a fire.
Questions
Survey, access, clean and certify. The survey measures the grease and finds the access; access provision opens up the whole run; the clean removes grease to below fifty microns; and certification verifies and documents the result with a report, photographs and a register entry.
Not without losing compliance. A clean with no survey is unscoped, a clean with no access is partial, and a clean with no verification has no proof. TR19 Grease treats the stages as a connected process, not optional extras.
Surfaces must be verified to below fifty microns of residual grease, checked visually and by a Deposit Thickness Test or Wet Film Thickness Test. The clean is triggered when the mean grease reaches 200 microns, or 500 microns at any single point.
A post-clean verification report with before-and-after photographs from identical positions and recorded deposit measurements, plus a certificate registered on the BESCA VHE portal and lodged on a national register.
Because you cannot price, scope or reach a system you have not inspected. The survey establishes the grease load, the worst areas and whether access exists - all of which decide how the clean is carried out.
Phoenix Duct Clean · by the numbers
We survey, provide access, clean the whole run to TR19 Grease and certify the result with a verification report - not a canopy wipe and an invoice.