A skim removes the grease cap and leaves the rest. A clean takes out the contents, then scrapes the walls, baffles and outlet tee back to bare surface, which is what actually restores the trap's retention time.
Grease trap cleaning is about retention time, not volume
A grease trap separates by slowing water down enough for grease to rise and solids to settle before the flow reaches the outlet. Everything occupying the chamber, including the settled layer nobody can see, reduces the volume available to do that.
Remove only the floating cap and the trap looks clean while its retention time stays short, so grease leaves with the flow within days. That is how a kitchen ends up on a cleaning contract and still getting blocked lines.
A proper clean removes the contents and then deals with the surfaces: the ring welded around the liquid line, the baffle faces, and the outlet tee, all scraped back. Intervals and paperwork are on grease trap compliance, and scheduled pump-outs on grease trap pumping.
Scraped to bare
How it works
How a trap clean runs
Booked around service
Early morning, after close or a dark day, so nothing happens while covers are going out.
Measure the fill
Grease cap and solids depth read and recorded before anything is removed, because those numbers set your next interval.
Remove and scrape
Contents drawn off, then walls, baffles and outlet tee scraped and washed down to bare surface.
Manifest and next date
Signed manifest left for your file with the recommended next service date on it, and a copy kept against the site.
What it prevents downstream
Grease that leaves the trap lines the pipe
Grease passing the trap cools in the run and coats the bore, narrowing it until anything at all will lodge. That is a drain excavation rather than a cleaning bill, and the repair is in the worst possible place, under a working kitchen floor.
On a property running on septic rather than sewer there is a second consequence. Grease reaching the tank floats and, if the outlet tee is worn, leaves with the effluent into the bed, where soil that has taken grease does not recover.
That is why kitchen sites are scheduled as a whole rather than trap by trap, under restaurant septic service, and why the tank's outlet tee matters as much as the trap does.
One quarter fullTrigger
Scraped bareSurfaces
Left on siteManifest
Grease trap services
Other grease trap work
Cleaning, scheduled pumping and the paperwork behind both.
Before combined grease and solids reach about a quarter of the working depth, which for most kitchens falls somewhere between monthly and quarterly. Menu matters more than seat count.
Pumping removes the contents. Cleaning also scrapes the walls, baffles and outlet back to bare surface, which is what restores retention time. See grease trap pumping.
We would rather not, and for most kitchens it is impractical. Tell us your hours and the route is built around them.
No. They can help with odour and line films but they do not remove the accumulated cap or the settled layer, and some emulsify grease so it passes the trap instead of being captured.
Often yes, because a larger trap costs more per visit but usually less per year through fewer visits. The fill readings tell us whether the case is real.
A signed manifest at every visit showing what was removed and where it went, with a copy filed against the site. See grease trap compliance.
