Rehabilitation methods
Trenchless sewer rehabilitation: the full toolbox
Sewer rehabilitation is a family of techniques, not one trick. Which one fits depends on the camera findings, the pipe's route, and what it connects to.
Rehabilitate, renew or replace
Engineers sort trenchless work into three categories. Rehabilitation restores a pipe's function while keeping the old pipe as part of the structure — cleaning, root cutting, grouting a leaking joint. Renewal builds a new load-bearing pipe within the old one — cured-in-place and spray-applied liners. Replacement removes or destroys the old pipe and installs a new one on the same line — pipe bursting, and in larger work, pipe reaming or directional drilling of a new run. Most residential jobs are renewal or replacement; most municipal programs use all three.
The methods
Cured-in-place pipe lining
The workhorse of renewal. A resin-soaked liner hardens inside the host into a seamless new pipe. Suited to lines that are damaged yet still hold their shape. Full explanation.
Pipe bursting
The workhorse of replacement. A bursting head breaks up the old pipe as new HDPE trails in behind. Suited to collapsed, bellied, flattened or undersized lines. Full explanation.
Sectional point repair
A liner 2 to 10 feet long, cured over a single defect such as a cracked bell or a root-damaged joint on an otherwise sound line. Typically $1,500 to $4,000 per defect, cured in an hour or two, and cheaper than a full liner when the camera shows one problem rather than a pattern of them.
Spray-applied and brush-cast lining
Epoxy or polyurea applied to the inside of the pipe by a rotating spray head or brush, in several coats of roughly 1 to 3 millimeters each, building up a structural wall. Used for under-slab cast iron with many bends, small-diameter drains, and systems where a felt liner cannot be inverted. Also used on larger pipe as a coating, where it is called spin casting.
Lateral reinstatement and connection seals
After a main is lined, each lateral is reopened from inside with a robotic cutter. Where the connection itself leaks, a lateral connection seal — a short liner shaped like a top hat — is cured into the junction.
Manhole and structure rehabilitation
Cementitious and epoxy spray linings, or cured-in-place manhole liners, stop infiltration at the structures that connect the pipes.
Grouting
Chemical grout injected through a packer at a leaking joint seals it from the outside. Stops infiltration on a sound pipe; does not add structure.
How the choice gets made
A single camera run drives the decision. Pipe material and diameter, the type and count of defects, slope, depth, groundwater, access at each end and what sits on the surface above the line. One defect on a good line: point repair. A pattern of defects on a round line: lining. A line out of shape: bursting. Tight bends under a slab: spray lining. A section no method can reach: a small excavation. A contractor with the whole toolbox proposes the method the footage calls for; a contractor with one tool proposes that tool.
The CIPP Verified installers listed by city on this site have had their equipment and completed work reviewed across these methods. Find yours through the state directory.
Common questions about rehabilitation methods
What is the difference between sewer rehabilitation and sewer replacement?+
Rehabilitation and renewal keep the old pipe in the ground and restore or rebuild it from inside (grouting, point repair, CIPP and spray-applied lining). Replacement destroys or removes the old pipe and installs a new one on the same line, which in trenchless work means pipe bursting.
Which trenchless method is best for a residential sewer line?+
CIPP lining for a pipe that is cracked, root-damaged or leaking at the joints but still round; pipe bursting for a pipe that has collapsed, bellied, flattened or lost its slope; a sectional point repair for a single defect on an otherwise sound line; spray-applied epoxy for under-slab drains with many bends. The camera inspection decides.
What is a lateral reinstatement?+
After a main is lined, every house connection is sealed over by the liner. A robotic cutter working from inside the main reopens each one, guided by camera. On a lined lateral the same cutter reopens branch lines such as a second cleanout.