Trenchless sewer line replacement gets sold as the answer to digging up your yard. It is a good answer, and it is not a universal one. Two different techniques hide under that one word, they need different things from the pipe you already have, and there are conditions where neither works and honest contractors will tell you so.
Central Ohio has a lot of vitrified clay tile in older neighbourhoods and a lot of mature trees planted over it, which is a combination that produces root intrusion and joint separation on a predictable schedule. So this decision comes up often here, and the sales pitch is usually louder than the diagnosis.
Nothing gets decided before the camera
Every legitimate version of this job starts with a camera survey of the line, with the head located from the surface as it goes so the depth and position of each defect are recorded rather than estimated.
What the camera answers is not just whether the pipe is damaged. It answers the questions that select the method.
What is the pipe made of? Clay tile fails at the joints. Cast iron corrodes from the inside and loses its bottom. Orangeburg, a bituminous fibre pipe used in some mid century construction, deforms into an oval and eventually collapses.
Is there a belly? A sag where the pipe has lost its fall and holds standing water. This is the single most important finding, because it is a grade problem, and no trenchless method fixes grade.
Is the line continuous, or is a section missing? A pipe with a fully collapsed section has no path for a liner or a bursting head.
Where are the connections and the bends? Every branch that joins the line has to be reopened after lining, and sharp bends limit what can be pulled through.
A contractor who quotes a method before the camera has been down the line is selling you their equipment rather than solving your problem. That survey is part of sewer line service and it should be the first line item on any proposal.
Trenchless sewer line replacement: the two methods and what each needs
Cured in place lining. A resin saturated liner is pulled or inverted into the existing pipe and cured, forming a new pipe inside the old one. The old pipe becomes the mould.
What it needs: a host pipe that is structurally continuous and reasonably round. Cracks and separated joints are fine. A collapsed section is not, because there is nothing to line against. It needs the line cleaned first, usually by hydro jetting and mechanical cutting, because roots and scale left in place become permanent bumps in the finished liner.
What it costs you: a small reduction in internal diameter, which is usually more than offset by the smooth bore. And every branch connection has to be reinstated after curing, typically with a cutter run from inside.
What it cannot do: fix a belly, fix grade, or increase capacity.
Pipe bursting. A bursting head is pulled through the old pipe, fracturing it outward, while new pipe is drawn in behind it. Usually the replacement is fused polyethylene, which arrives as one continuous jointless length.
What it needs: an access pit at each end, a reasonably straight path, and soil that will accept the fragments of the old pipe being pushed outward. It also needs a safe distance from other buried utilities, since the process disturbs the ground around the pipe.
What it gives you: a genuinely new pipe with no joints for roots to find, and the option to increase the diameter.
What it cannot do: follow severe bends, or work where the fractured pipe has nowhere to go.
When open cut is the honest answer
Some conditions rule both methods out, and a contractor who will not say so is one to avoid.
A belly has to be re-graded, which means excavating and rebedding that section. Lining a sag gives you a smooth sag.
A fully collapsed length has no continuous path, so a liner has nothing to cure against and a bursting head has nothing to follow.
Severe offsets, where two sections have shifted far enough that the bore no longer lines up, can defeat both.
Sometimes a hybrid is the right answer: open cut the eight bad feet, then line or burst the rest. That is a good proposal, not a failed one.
What actually happens in your yard
Trenchless does not mean no digging. It means less.
Lining usually needs access at a cleanout or a small pit, plus room for the equipment and, on some systems, a boiler or steam unit at the curb. Bursting needs a pit at both ends, one of which is normally at the house and the other near the connection to the main.
That end pit is the part people are least prepared for, because it is often in the front garden or under a driveway edge. Ask where both pits go, how deep they will be, and who restores the surface. Restoration should be a named line item, not an assumption.
Landscaping over the line is also relevant. Mature tree roots that caused the problem may need work, and the tree may not survive an aggressive excavation next to it. Better to know that before the machine arrives.
Where your responsibility ends
The lateral runs from the house to the connection at the public main. Which portion of that is the property owner’s responsibility varies by jurisdiction, and in some places the owner’s responsibility runs all the way to the main including the section under the street.
This matters because the work in the right of way is a different permit, sometimes a different contractor qualification, and often a traffic control requirement. Establish where the boundary sits for your address before you compare quotes, because two proposals covering different lengths of pipe are not comparable.
What a good proposal contains
It should include the camera survey with the located depths and positions of the defects, and it should hand you that footage. It should state the pipe material and diameter found, and the length being addressed. It should name the method and say why that method was chosen over the other two. It should state where the access pits go and who restores the surface. It should say how branch connections are reinstated. It should say what happens if the crew finds something the camera did not show, because on a buried line that is a real possibility and the honest response is a stated procedure rather than silence. And it should give the warranty on the new pipe and on the workmanship separately.
If you want the camera survey done before anybody quotes a method, start at the contact page. Our trenchless sewer work sits inside the wider drain services department, and the plumbing team handles the interior side of the same line.
Frequently asked questions
Does trenchless sewer replacement mean no digging at all?
No, and any contractor who says so is overselling. Lining generally needs access at a cleanout or a small pit plus space for equipment. Pipe bursting needs a pit at each end, and the far pit is usually near the connection to the main, which often means the front garden or the edge of a driveway. What trenchless avoids is a continuous trench along the whole length of the line, which is a large difference, just not the same as no digging.
Can a liner fix a sewer line that holds standing water?
No. A belly is a grade problem: the pipe has lost its fall and water sits in the low spot. A liner takes the shape of the pipe it cures inside, so lining a sag produces a smooth sag that still holds water. The only real fix is excavating that section and rebedding it to the correct fall. A contractor proposing a liner over a known belly either did not locate it or is hoping you will not notice.
Which is better, lining or pipe bursting?
Neither, in the abstract. Lining suits a pipe that is cracked or has separated joints but is still continuous and reasonably round, and it disturbs the least ground. Bursting suits a pipe that is badly deteriorated or too small, because it replaces the pipe entirely and can increase the diameter, but it needs pits at both ends and a path clear of other utilities. The camera survey chooses between them, not the sales conversation.
How long does the work take?
The pipe work itself is usually a day or two for a residential lateral once everything is on site, and the curing or fusing step is a matter of hours. What extends the schedule is everything around it: the camera survey and locating, cleaning the line, permits, and any work in the public right of way, which can carry its own requirements. Ask for the sequence rather than a single number.
Am I responsible for the sewer line under the street?
Often yes, and it varies by jurisdiction, which is why it matters so much when comparing quotes. In many places the property owner is responsible for the lateral all the way to the connection at the public main, including the portion under the roadway. Work in the right of way usually carries a separate permit and sometimes traffic control. Confirm where your responsibility ends before you compare proposals, because two quotes covering different lengths of pipe are not the same quote.