Sewer Line Repair Under a Slab in New City and Rockland County

New City Trenchless performs sewer line repair under a slab by rebuilding the pipe from its ends: an epoxy-saturated liner installed through a cleanout or one small access pit, so the finished floor over the run never gets opened. In Rockland County’s split-levels and ranches that matters more than anywhere, because the pipe under the slab is usually the original cast iron.

Why the Slab Comes Up Last, Not First

A finished basement sits on top of that pipe: tile, laminate, a workshop slab, in newer pours sometimes radiant heat loops. Chasing a failure by breaking concrete means demolition dust, spoil carried through the house, and a patch that never quite matches the surrounding floor. Trenchless flips the order of operations. Prove exactly where and what the failure is first, repair through existing openings second, and cut the floor only if the pipe’s geometry forces it.

Repairing a Pipe You Can Only Reach from Its Ends

Inverted lining through a cleanout

A felt liner tube saturated with epoxy resin is turned inside-out into the line from an inversion drum, pressed against the host pipe by a calibration tube, then cured with ambient or steam cure depending on run length.

Pull-in-place between two access points

Where both ends of the failed section can be reached, the liner is winched into position between them and cured, useful when only part of the under-slab run has failed.

Sectional point repair

One bad joint under the footprint takes a short sleeve over that joint alone. After any cure, a robotic reinstatement cutter reopens branch connections from inside the pipe.

Mapping the Run Before Anything Is Cut

The camera goes in first, carrying a locating sonde. From above we trace the line’s path across the slab and read its depth, logging the house trap, each wye fitting and the lateral tap connection as the camera passes them. The map is what turns “the pipe is somewhere under the family room” into a mark on the floor accurate enough to plan around.

Where the Access Pits Actually Go

First choice is no pit at all: an existing cleanout or two-way cleanout is the entry. Second choice is a small pit outside the foundation wall, at the marked point where the interior pipe exits the footprint. Last resort is a single precise floor opening over a fitting, a couple of feet square, cut where the sonde says and nowhere else. Pit placement comes off the map, never off a guess.

Cast Iron Under Rockland Slabs, Orangeburg Beyond Them

Postwar builders here ran cast iron pipe under the footprint and switched materials at the foundation wall, to clay tile or to Orangeburg pipe from the factory ten miles away in Orangeburg NY. Under the slab, cast iron fails by channeling: the invert erodes away along the waterline while the visible crown still looks sound, and scale buildup narrows what remains. Lining rebuilds that missing invert in place. Out in the yard, the Orangeburg run fails on its own schedule, which is why a common under-slab job in New City is a hybrid: line the interior cast iron, then pipe burst the yard section with new HDPE pipe in the same mobilization.

What Lining Cannot Fix Under a Slab, and What It Costs

A liner follows the host pipe exactly, so a bellied pipe or a run that has lost its fall stays that way inside the new liner. When the camera shows standing water in a low spot under the footprint, the honest recommendation is a targeted floor opening at that section, not a liner over the problem.

Open-cut through a finished floor typically lands at 1.5 to 2x the trenchless price for the same line once concrete removal and floor restoration are counted.