Trenchless and excavation methods
The methods here are ways of getting the work done. They are frequently marketed against each other, and the marketing tends to compress into "no-dig is better", which is not a statement anyone can support in general.
Each page explains what the method attempts, what has to be true for it to apply, what it disturbs, and what to clarify in a proposal that offers it.
What this page cannot establish
- no method here is presented as better than another — that depends on your property
- SewerOwner cannot establish that a method is suitable for your line
- "no-dig" describes surface disturbance, not quality or durability
- no lifespan, warranty outcome, or performance claim is made for any method
Methods
- Open-cut excavationUnderstand what traditional excavation involves and what to clarify if it is proposed.
- Cured-in-place liningUnderstand what cured-in-place lining involves and what to clarify if it is proposed.
- Sectional liningUnderstand what sectional lining involves and what to clarify if it is proposed.
- Pipe burstingUnderstand what pipe bursting involves and what to clarify if it is proposed.
Trenchless and excavation at a glance
Cured-in-place lining
Installing a liner inside the existing pipe that hardens in place.
Create a new pipe wall inside the existing line, using the existing pipe as the host, without excavating the full route.
Cannot establish: that lining is appropriate for a given line without inspection; the condition of the ground around the host pipe; that the host pipe’s surroundings are unaffected; that this method is preferable to any other for a given property.
Sectional lining
Lining a defined length within the line rather than its full run.
Place a liner across one identified length, leaving the rest of the line as it is.
Cannot establish: the condition of the line outside the placed length; that the identified condition was the only one present; that no further work will be needed.
Pipe bursting
Pulling a new pipe along the existing route while displacing the old one.
Replace the pipe along its existing route by drawing new pipe through while the existing pipe is displaced outward, using pits rather than a full-length trench.
Cannot establish: that the route is suitable without site-specific assessment; the position of other buried services; that this method is preferable to any other for a given property.
Traditional excavation
Digging along the line to expose and replace pipe directly.
Expose the line so that pipe can be removed and replaced, and so that what is uncovered can be observed directly.
Cannot establish: the condition of any section outside the excavation; that no further conditions exist elsewhere; that the new installation will perform for any stated period.
Rerouting
Installing the line along a different path rather than the existing one.
Establish a new route for the line where the existing route presents difficulties that a same-route method would not resolve.
Cannot establish: that a new route is permissible without checking; that the new route avoids all obstructions.
What would change the answer
- what the inspection established about the host pipe and its configuration
- the route, approximate depth, and length
- what surfaces and services the route crosses
What to do next
It is the baseline every other method is compared against, and understanding it makes the comparisons legible.
Start with open-cut excavationIf your situation is different
- You want the repair and replacement options generally: Repair and replacement approaches
- You are ready to compare written quotes: Compare proposals by stated scope
Related, and why
- Method questions
What to ask about why one method was proposed rather than another.