Sewer pipe relining: what happens on the day

Before the day

The relining day only goes smoothly because of an earlier visit. The pre-inspection recorded the run, measured its length to the foot, noted the diameter and every bend, and found the cleanout or decided where one would be installed. From that recording the liner was cut to length and the resin quantity calculated. The owner was told how long water would be off and whether the city needed to inspect anything.

Morning: cleaning

The crew sets up at the cleanout and runs a hydro jetter down the line. Water at high pressure strips grease, scale and sediment; a root-cutting nozzle takes roots back to the pipe wall. A second camera run confirms the pipe is clean to bare wall along its whole length and that nothing — a protruding tap, a dropped joint — will snag the liner. Anything that would is ground away with a cutter now, not discovered halfway through an inversion.

Late morning: wet-out

The dry liner is laid out, the resin mixed and poured in, and the liner run through pinch rollers under vacuum so the resin fills the felt evenly from end to end. The time between wet-out and cure is limited by the resin's pot life, which is why the crew will not start wet-out until the pipe is confirmed ready.

Midday: installation and cure

The wet-out liner enters the pipe at the cleanout by inversion or winch and inflated against the wall. Hot water or steam is circulated for the cure, usually two to four hours for a lateral, with temperature logged throughout. During this time the house's water stays off. When the cure is complete the liner is brought down in temperature gradually so it stays tight to the host, and the ends are trimmed flush.

Afternoon: reinstatement and video

If the line has branches — a second cleanout, a tie-in from a garage bathroom — each one is reopened from inside with a camera-guided cutter. A final camera run records the finished pipe along its full length; that video is the owner's record of the installed pipe, and it should be handed over, not just offered.

What can go wrong, and how it is prevented

• Lifts and wrinkles where the liner did not seat against the wall — prevented by correct sizing and inflation pressure, and caught on the final video.
• Resin migration into a branch, sealing it — prevented by plugging branches before installation and reinstating them afterward.
• Short cure leaving soft resin — prevented by logged temperature and time, never by a crew's watch.
• Lining a belly that still holds water afterward — prevented by the pre-inspection, which should have ruled the line out for lining in the first place.

Relining contractors listed on this site are found through the state directory. Estimates are free and start with that first camera run.