No mystery to it. Here is exactly what happens from the moment you call to the moment we hand the job back.
The crew checks grease depth, locates access panels, notes any inaccessible sections, and photographs the starting condition. Inaccessible areas must be recorded on the report, not quietly ignored.
Cooking surfaces, prep tables, and floors are tented and covered, and a wash water catch is set under the hood. This happens before any chemical is sprayed.
Hot caustic degreaser applied and given dwell time, then hot pressure washing from the fan down through the duct into the hood so grease travels one direction.
Rooftop fan cleaned in place or lifted, blades and housing washed, fan belt condition checked, and the grease containment box emptied or replaced.
Filters reinstalled, stainless polished, protection removed, and the kitchen returned to service condition. The roof gets checked for runoff so grease does not sit on the membrane.
Service report, before and after photos, and a dated compliance sticker on the hood showing the service date and next due date. Keep these where an inspector can be handed them.
None of this is required — it just makes the visit quicker.