“No dig” trenchless sewer repair refers to several methods of sanitary sewer line repair without any digging or excavation. These advanced trenchless technologies have revolutionized sewer and pipe repair, though they may still not be the best choice in every possible situation. There are also a lot of misconceptions about trenchless methods, so it’s important to get honest, reliable information before you hire someone to repair your sewer.
No-dig solutions use existing access points, which minimizes or even eliminates damage and disruptions to landscapes, hardscapes, and property while providing reliable, long-lasting sanitary sewer repairs. The very latest repair technology – and the one we recommend and provide – is “Blue Light” UV-cured epoxy pipe lining, which is extremely controllable and quick-setting compared to earlier methods. But different contractors use other trenchless sewer technology and methods, and we’ll help you understand those as well.
There are also “Low-Dig” trenchless solutions that do require some excavation but not a full open trench. These are great options in many cases, and we’ll discuss them here as well, but they are a little different from truly “No Dig” methods.
Cured In Place Pipe (CIPP) Lining (or “Relining”)
Cured-in-place-pipe lining is probably the most common no-dig trenchless pipe repair method. In most cases, a fiberglass or felt sock soaked with a liquid epoxy resin is inserted into the damaged sewer (often via inversion, where it is initially inside out). The sock is then inflated in the existing pipe with air, and cured (hardened) by some method, usually either heat or UV light.
The heat-cured method (usually steam or hot water) is the older method and is reliable when installed properly, but there are pitfalls that the newer UV light-cured method avoids, guaranteeing proper installation.
No-Dig, Heat-Cured CIPP Pipe Lining
The older heat-cured trenchless pipe lining method is still widely used, and it is an effective method when installed properly. There are a few issues that can complicate an installation, however, and require time-wasting and expensive corrections.
First of all, the heat-cured epoxy must be mixed on-site because it starts slow-curing immediately. This puts pressure on the installer, as once the curing starts the epoxy-soaked sock must be put into place quickly, and any mistakes may not be fixable before the epoxy hardens too much.
Second, the heat-cured epoxy takes a long time to cure, typically something like twelve hours. Again, this is time when something could go wrong, like loss of air pressure keeping the new lining round. It also means that the new pipe can’t be inspected and used until the next day, usually.
No-Dig, UV-Cured “Blue Light” CIPP Pipe Lining
With the latest blue light curing technologies, the fabric sock is soaked in an epoxy resin that cannot cure by itself. So unlike the heat-cured method, where the epoxy starts to harden as soon as it is mixed and places a time limit on insertion and perfect placement, the installer can take as much time as needed to position and verify every aspect of the process without worrying about a time limit. Only when everything is in place and verified does the hardening process begin by turning on the UV-light system inside the pipe.
The light curing is also completed very quickly compared to the heat curing method – within minutes! So again, the chances of some aspect of the process going wrong over that short time period is extremely low versus the several hours required to fully harden the heat-cured epoxy.
The fast curing time also means that the sewer line can be inspected and put back into use the same day, rather than preventing sewer use by the homeowner or building until the next day.
No-Dig “Spray Lining” Methods
Spray lining, also known as spray-applied pipe lining, is another “no dig” technology used to rehabilitate deteriorated pipes by coating their interior surfaces with specialized polymer materials. These materials, such as epoxy, polyurethane, or polyurea, create a durable, seamless lining that makes the existing pipe usable. It requires the original pipe to be in good structural condition, so if the pipe is broken or has bellies, it may not be a suitable application.
Spray lining is a good solution for extending the life of a pipe with a corroded interior that is in otherwise good condition, but for many sewer problems, epoxy lining is the better (or only) no-dig choice for trenchless repair.
Can “No Dig” Repair Method Be Used for Complete Sewer Replacement
CIPP relining can definitely be considered for complete pipe replacement. The entire length of a host pipe can be lined with an epoxy liner that can be expected to last as long, or nearly as long, as a full excavation and installation of an entirely new pipe.
Pros and Cons of a No-Dig Trenchless Sewer Line Repair
Pros of No-Dig Sewer Repairs
When appropriate, no-dig trenchless sewer repair offers numerous advantages over traditional excavation methods. One of the most significant benefits is the minimal disruption to landscapes and property. This repair technique preserves lawns, trees, driveways, basement slabs, and other surface structures. It also usually results in faster completion times, reducing the inconvenience to property owners.
The non-invasive nature of no-dig repairs also makes them ideal for use in environmentally sensitive areas or locations where excavation would be challenging or prohibited.
Cons of No-Dig Sewer Repairs
While no-dig trenchless sewer repair offers many benefits, there are some potential drawbacks to consider. One limitation is that not all types of pipe damage are suitable for trenchless repair methods. In some cases, especially with severely collapsed or misaligned pipes, traditional excavation may still be necessary.
Also, in some instances, access points for the trenchless repair equipment may still require some excavation, although this is typically much less extensive than traditional methods. It’s important for property owners to consult with experienced professionals to determine the most appropriate repair option for their specific situation.
Is Pipe Bursting a “No Dig” Trenchless Method
We would classify trenchless pipe bursting as “Low Dig” rather than “No Dig.” It is an extremely effective trenchless underground repair method, however, and we often prefer it to CIPP in many cases because it places an entirely new pipe with the same diameter as the old, damaged pipe with minimal excavation required.
Pipe bursting requires the excavation of two pits, one at each end of the pipe to be repaired (replace, actually).
The pipe bursting process pulls a large bursting head through the pipe, fracturing it outward while a seamless new HDPE pipe is drawn in behind it. The fragments of the old pipe are displaced into the surrounding soil. This method is highly efficient for complete pipe replacement without the need for extensive trenching. It’s especially useful in urban areas or locations where minimal surface disruption is crucial. While some excavation is required for access points, pipe bursting significantly reduces the overall digging compared to traditional sewer line replacement methods, preserving landscapes and surface structures.
Is Hydrojetting a “No Dig” Trenchless Pipe Repair Method?
Hydrojetting could be considered a “no-dig” trenchless method if the required repair is simply the removal of buildup inside the pipe to reestablish proper function, but it will not address leaks or broken pipes. It is a rehabilitation technique rather than a patch or lining.
This powerful technique utilizes high-pressure water jets and a large volume of water to remove stubborn clogs, tree roots, mineral scale, grease buildup, and other debris that can accumulate in sewer lines over time. It’s a non-invasive method that requires no excavation, making it an excellent option for maintaining and cleaning sewer systems without disturbing the surrounding landscape.
Hydrojetting also plays a crucial role in preparing a line for CIPP remediation. Hydrojetting is used to clean and clear the existing pipe and make the interior of the pipe suitable for lining.
Is Chain Knocking a “No Dig” Trenchless Sewer Repair Method?
Chain knocking, also known as chain flailing or chain scraping, can also be considered a “no-dig” trenchless repair method of simply opening up and smoothing pipe surfaces is sufficient. This technique involves inserting a specially designed chain into the sewer pipe, which is then rotated at high speeds to remove built-up rust, scale, and encrustations from the interior pipe walls.
Like hydrojetting, chain knocking is used to prepare the interior of an existing pipe for CIPP relining. Chain knocking requires no excavation and can be performed through existing access points, making it a true trenchless method.
No-Dig Sewer Repair Cost
The cost of no-dig trenchless sewer repair can vary widely depending on several factors, including the extent of the damage, the length of pipe requiring repair, the specific method used, and the local market conditions. Full excavation is the ultimate solution, as a perfect new gravel bed can be placed under the new pipe, the angle of the pipe can be verified, and the entire project can be visually inspected before being filled in. However, if open excavation would damage more than just grass and dirt, trenchless methods often prove more cost-effective in the long run. For example, a typical pipe lining project might range from $80 to $250 per foot, while pipe bursting could cost between $60 and $200 per foot.
Service Force Plumbing: Your Best Choice for Trenchless Sewer Repair Services
Contact Service Force Plumbing for your local No-Dig trenchless sewer repair or replacement, and let us handle your damaged sewer line. We offer best-in-class service with the latest no-dig blue light UV-cured epoxy pipe lining solutions, as well as pipe bursting, traditional excavation, chain knocking, and hydro jetting to cover your every sewer repair need.
About the Author: Roy Barnes is co-owner and the service manager at Service Force Plumbing. He has decades of sewer repair experience and has been widely consulted about sewer and drain issues for national publications like the Washington Post, US News and World Report, and Family Handyman.
