What “collapsed” can mean
Homeowners may use collapsed to describe any serious backup. Camera footage may instead show heavy scale, standing water, an offset joint, a broken section or a truly closed pipe. The distinction changes the repair.
Why a complete collapse blocks lining
Installation equipment and the liner must travel through the route. If the pipe has lost continuity or usable diameter, a liner cannot simply pass through solid soil or a crushed section.
Targeted excavation may restore continuity
In some projects, the failed spot can be exposed and repaired, creating access or continuity for evaluation of the remaining run. Whether a combined repair is sensible depends on the full condition.
Standing water is not always collapse
A belly or low point can hold water even when the pipe wall remains present. Lining follows the host-pipe geometry and generally does not correct grade, so drainage performance must be evaluated separately.
Severe offsets and transitions matter
A liner can conform to many bends and changes, but excessive offsets, diameter changes or branch conditions may be unsuitable for a specific system.
Demand a qualification explanation
Ask the contractor to show the footage and explain preparation, access, sizing, reinstatements and any condition that could prevent completion.