Process & access
Your certificate is only as good as the survey behind it. A thorough survey is what lets the certificate say something accurate and defensible - full or partial, and exactly what was done.
The short answer
It is tempting to think of the certificate as the thing that matters and the survey as a preliminary. In fact the certificate is only as trustworthy as the survey that underpins it. The survey establishes what the system was like before, where the grease sat and what was reachable; without that baseline, a certificate is just an assertion. With it, the certificate becomes a documented, defensible record of a real change - which is exactly what an insurer or fire risk assessor needs it to be.
What the survey gives the certificate
A detailed survey does two things for the certificate. First, it provides the before-state: the grease readings in microns from a Wet Film Thickness Test or Deposit Thickness Test, and the condition of each part of the system. That baseline is what the post-clean verification measures against, so the certificate can show a genuine before-and-after rather than an unsupported claim that the system is clean.
Second, the survey establishes what could actually be reached, which decides whether the certificate can honestly say 'full'. If the survey finds parts of the system with no access, then either that access is provided and the whole system is cleaned - supporting a full-clean certificate - or it is not, in which case the certificate must record a partial clean. Either way, the survey is what makes the scope on the certificate true rather than optimistic.
From survey to defensible record
When the survey is thorough, the certificate at the end can be specific and complete: the surfaces verified below fifty microns, the before-and-after photographs from matched positions, the deposit readings recorded, and the clean lodged on a register - typically via the BESCA verification portal - so it can be checked independently. That is a document with substance behind every line, and it is what stands up when a claim is assessed or a premises reviewed.
A weak or absent survey produces the opposite: a certificate that says the system is clean but cannot show against what, cannot prove the concealed runs were reached, and may quietly overstate the scope. If the system's compliance is later questioned - after a fire, or during an insurance review - that gap is where a certificate falls apart. The detail in the survey is precisely what determines whether the certificate protects you or merely reassures you. One is worth having; the other is not.
The survey is where a good certificate is really made
A defensible certificate is not produced at the end of the job - it is set up at the start, by a survey detailed enough to give it a baseline and an honest scope. Clean to the reading, verify from matched positions, and record the result truthfully, and the certificate becomes real proof. Skimp on the survey and the certificate has nothing to stand on.
Questions
Because the certificate is only as trustworthy as the baseline behind it. The survey records the before-state and what could be reached, so the certificate can document a real, measured change rather than an unsupported claim.
The before readings in microns from a WFTT or DTT and the condition of each part of the system, which the post-clean verification then measures against to show a genuine before-and-after.
Only when the whole system was reachable and cleaned. If the survey finds areas with no access, either that access is provided or the certificate must honestly record a partial clean.
Surfaces verified below fifty microns, before-and-after photographs from matched positions, recorded deposit readings, and the clean lodged on a register so it can be checked independently.
A certificate that claims the system is clean but cannot show against what or prove the concealed runs were reached - the kind of gap that falls apart if compliance is questioned after a fire or during an insurance review.
Phoenix Duct Clean · by the numbers
We survey in detail, clean to the reading, and certify honestly - a verification report and register entry that say exactly what was done, so it stands up when it matters.