The first maintenance visit is the baseline. The sewer line is cleaned, the camera documents what the pipe looks like without the buildup, and the technician sets an initial interval based on the severity of what was removed, the pipe material and condition, and the risk factors present on the property - root exposure, grease use, pipe age, household size. That initial interval is an educated estimate based on what the first visit reveals.
The second visit is where the schedule gets real. The camera documents how much buildup accumulated since the first cleaning. If the pipe is nearly clean at the scheduled return, the interval can extend - the pipe holds longer than expected, and the next visit is pushed further out. If the buildup has returned aggressively, the interval tightens - the pipe accumulates faster than anticipated, and the next visit is pulled closer. By the third visit, the schedule is calibrated to the pipe's actual behavior, not an estimate.
Each subsequent visit follows the same pattern: jet the line, camera the result, compare to the prior visit, adjust the interval. Over multiple visits, the maintenance record shows a clear trend - whether the pipe is stable, whether buildup rates are changing, and whether new conditions are developing between cleanings. A root entry point that was minor at the first visit but has grown by the third is caught on footage months before it produces a blockage. A section of wall that was intact at the baseline but shows early corrosion at the fourth visit gets flagged for monitoring before it becomes a crack. That trending is what separates scheduled maintenance from repeated one-time cleanings.