Introduction
Sewer repair is a big deal in many ways. First, a malfunctioning sewer pipe usually creates a fairly unpleasant environment. There can simply be disagreeable odors inside or outside the home, or there can be water and sewage backups into the home that can cause significant damage to the home, as well as be a health hazard to its occupants.
Second, sewer pipes are typically several feet underground and potentially under a concrete basement slab, a driveway, trees, or carefully planned landscaping and hardscaping. This means that the time, effort, and skills needed to access and repair the sewer are usually pretty expensive; plus, if the basement concrete or outdoor features have to be damaged or removed, it creates even more expenses on top of simply repairing the sewer line.
The good news is that professional plumbers now have several options for sewer repair besides simple excavation, and in many cases, the repair can be done without damaging other aspects of the property. Even so, sewer repair is still a big deal. It shouldn’t be postponed, and the technology and skill required to do it properly is still a big financial expense.
In this article, I’ll discuss everything a homeowner needs to know to face this big job, get it done right the first time, and keep costs as low as possible, given the specific situation.
How do you know that you need sewer repair?
Blocked drains or toilets. Most of the time, a damaged sewer line is first identified due to a major backup or repeated backups. Once a backup is cleared (usually with a drain snake), a specialized fiber optic sewer camera can be used to inspect the inside of the pipe and determine whether there are specific issues
Slow drains. Drains that drain slowly can be an indicator, too, as they are often caused by partial blockages of some type. Depending on the situation, your plumbers may be able to do an immediate camera inspection, or they may need to clear the drain first with a snake or water jetter to allow the use of a camera to identify any issues with the sewer pipe.
Green grass, wet areas, and foul odors. A crack or hole in your sewer line can leave signs, even if you aren’t (yet) experiencing blockages. You may see wet areas and smell foul odors in your basement or yard, and you might even see a particularly “well-fertilized” green patch on your lawn. Again, the sewer camera is the modern tool of choice for inspection versus the old-school method of digging up the grass and seeing if there is, in fact, a problem!
Home Inspection Results. If you are thinking of buying a house, having a sewer camera inspection is a smart choice, given the potential expense of repair. Some cities and states are even beginning to require it as part of every sale. If such an inspection identifies problems, immediate repair or replacement may be desirable either before or after purchase.
What kind of situations require repair?
Scale and Rust. Over time, especially with older homes, scale and rust can build up inside the sewer line. This can cause repeated backups as the diameter of the pipe is narrowed and rough or jagged surfaces can catch and hold debris.
Bellies. Bellies are low points in a line where standing water tends to collect. They are problematic because standing water slows the flow of debris. If you can imagine riding a water slide and then coming to an abrupt stop when you hit the pool at the bottom, you get the idea.
Cracks. Sewer pipes can crack for a variety of reasons, but once a crack appears, it is only a matter of time before backups occur. Dirt can work its way in, and tree roots will seek out the wet area around the crack.
Offsets. Cracks can also lead to offsets, where the ends of the pipe no longer match up. This narrows the effective diameter of the pipe, in addition to the other problems that come with cracks.
Root intrusion. Once the tiny pilot roots of a tree get access to the interior of the sewer pipe, they will multiply quickly and partially or completely block the pipe. While these roots can be removed using a “roto-rooter” or another tool, they will keep coming back, and each time they do, they will damage the pipe a little more. Repair or replacement is the only permanent solution.
Holes. Holes can also appear in pipes due to rust or other reasons. The most common type of “hole” in a pipe is where the bottom simply rots away and leaves a lengthwise “crack” where the bottom of the pipe is actually just dirt that sewage will seep into.
What methods of repair are available?
COMBINATION DESCALE AND HYDROJET
Sometimes, we encounter a problematic sewer line whose interior is filled with jagged scale and rust, causing backups, but there are no other issues like bellies, offsets, or roots.
In many of these cases, we can rehabilitate these pipes and get many more years of use out of them by using a mechanical descaling machine to remove the scale and rust and then washing all that debris out of the line using an ultra-high-volume water jetting device.
The result is a sewer pipe that is not brand new but has a smoothed interior that is back to its original diameter, typically for a lower total cost than actually repairing or replacing the pipe itself.
In some cases, the descaling and hydrojetting process will uncover more significant problems in the line that were hidden by the scale and rust, and in that case, some repair will be needed. But in our experience, these “new” issues tend to be localized and can be addressed by patching rather than complete replacement.
If descaling and jetting is an option in your case, it is important to ensure that the plumber you employ has top-notch mechanical descaling equipment and an industrial-strength jetter to fully clear the line. If your plumber shows up with a “jetter” that can be pulled along by hand rather than mounted to a truck or trailer, be suspicious.
The benefits of mechanical descaling and jetting include:
A less expensive process that requires no digging or trenchless repair.
The potential downsides, compared to other methods, include:
They can only address a line with no cracks, bellies, or offsets.
The original line is still in place and will naturally have a shorter lifespan than a completely new line.
Many plumbers will not own a high-enough volume jetter to completely flush out debris, potentially making the pipe even more prone to clogging than it was before.
Check out the video below for an animation of the descaling and hydrojetting process:
TRENCHLESS PIPE BURSTING
Trenchless pipe bursting is one of the two most common trenchless pipe repair and replacement methods, one which we both provide and endorse. It is particularly suited for replacing a long section (usually the entire length) of a sewer line, as it does require excavating access pits at one or both ends of the section to be replaced.
The method involves running a cable through the old line and then using a powerful hydraulic pump to pull a metal, cone-shaped “bursting head” through the old pipe while pulling a new, full-sized HDPE seamless pipe behind it. The bursting head is bigger than the diameter of the old pipe and forces the pipe to break apart or “burst” as the powerful hydraulic machine pulls the bursting head through the pipe, inch by inch. The broken pieces of pipe are simultaneously pushed out of the way and pressed against the surrounding earth while the new replacement pipe is pulled through.
The benefits of trenchless pipe bursting include:
A fully formed, perfectly round, full-sized, full-diameter pipe replaces the old pipe while saving lawns, landscaping features, walkways, paved surfaces, and potentially interior floors.
As the old pipe is broken apart and pressed against the surrounding earth, some amount of extra support for the new line is created.
The pipe is made and sealed outside the pipe, meaning that its quality can be inspected and assured before it is pulled underground.
The potential downsides, compared to other methods, include:
Two dig pits are required at each end, and concrete or paving may need to be broken apart to allow those pits to be dug, depending on the specific situation.
There is no way to know – for sure – the amount of support that exists around the new pipe. In most cases this is not a problem, but in rare cases water in the soil or some other issue has undermined the bed and surrounding dirt more than is typical.
This system is not viable for patching short sections of damage, given the need to dig holes for each section.
Check out the video below for an animation of the pipe bursting process:
TRENCHLESS PIPE LINING AND PATCHING
Epoxy cured-in-place pipe, or “CIPP,” is a trenchless repair and replacement method that has been around for many years. However, we have always avoided it because the original process used heat, like steam or hot water, to cure the lining, and there were lots of things that could go wrong during the process.
For example, the epoxy resin has to be mixed on-site, and the hardening process begins immediately, even without actively applying heat. So, once you start the process, you are working against the clock and under some amount of pressure.
At the same time, the epoxy cures very slowly, even once exposed to a heat source. This means that once the epoxy lining is in place, it requires several hours to cure before the lined pipe can be inspected and declared ready for use. If something has gone wrong in the process—if, for example, the liner sagged while hardening—then it will be several hours or even the next day before the error can be discovered and action taken to fix it (and it’s often not an easy fix!).
So, in the past, trenchless pipe bursting was such a reliable process that it didn’t make much sense to invest in another, less reliable process, even if it required less digging.
However, with the advent of the ultraviolet (UV-cured) lining process, our outlook has completely changed, and we have made big investments in the technology.
With UV CIPP lining (we use the Lightray system by Perma-Liner), the epoxy does not begin to harden until it is exposed to UV light. So the epoxy can be mixed in advance, the liners can be prepared in advance, and the liners can be placed inside the pipe and adjusted and inspected within the complete darkness of the old sewer pipe with no pre-hardening until the technicians are fully satisfied that the liner is placed correctly, that it is perfectly round, that all the equipment is working properly. This ability to take the time to ensure that everything is correct without the pressure of already-hardening heat-cured epoxy almost completely eliminates the chances of any problems with the final product.
Once our technicians begin the curing process by activating the UV light emitter, it only takes a few minutes, the hardened liner can be immediately inspected, and the sewer line can be declared ready for use.
Another great thing about CIPP processes is the ability to patch short sections of a sewer line if the pipe is generally in good shape but is compromised in specific places, whether due to bellies, cracks, root intrusion, or other reasons.
When patching is an option, it can be a great money saver for a homeowner. Whether it’s a three-foot section, a ten-foot section, or a twenty-foot section, the ability to repair only a specific length of the pipe opens up a lot of options depending on each customer’s individual situation.
The benefits of trenchless pipe lining include:
The process often requires no digging, as the equipment to insert and cure the liner takes up little space and can be placed directly into the old sewer pipe.
The UV-cured process can be completed relatively quickly compared to methods that require digging, although this isn’t typically true for the heat-cured process.
The ability to patch short sections of line, usually at a lower cost, rather than lining or replacing the entire sewer pipe.
The potential downsides, compared to other methods, include:
The new liner does not gain any extra support from filling in the ground around it, as you would with a conventional dig or (to some degree) trenchless pipe bursting.
The diameter of the new liner is slightly smaller than the original pipe, meaning there is marginally less room for sewage and other debris to flow through it. Many manufacturers claim, however, that the surface of the liner is so slick that it negates the flow loss of the smaller diameter. Whether this is true or not, however, the benefits of trenchless CIPP can significantly outweigh any concerns about the slight reduction in diameter.
Check out the video below for an animation the ultraviolet CIPP patching process:
CONVENTIONAL DIG (TRENCH EXCAVATION)
For centuries, of course, excavating the damaged sewer pipe to repair or replace it was the only available option, and all other things being equal, it is still the most reliable method for sewer repair. When you dig a trench to expose the old pipe, you are able to lay down a perfect bed of gravel at just the right grade and install solvent-welded super-hard PVC that performs perfectly for decades of use. And as you fill the trench and cover the pipe, you can visually inspect and ensure that the fill fully supports the pipe, as opposed to trenchless methods where you cannot fully verify the state of the support around the new pipe.
Sometimes a conventional dig is the only option. For example, a completely collapsed sewer pipe will prevent a trenchless method from being inserted through the old line reliably, or at all. If this is the case, you will want to ensure that you choose a plumbing company that owns their own excavating equipment and has years of experience using it.
How do you choose the right sewer repair solution?
There are three key factors that will influence the choice of sewer repair method for any given situation:
Type and extent of damage to the line. As discussed above, simple scale and rust may be correctable with a basic mechanical descale and hydrojetting, while a single crack or root intrusion might be patchable with a localized dig or a section of cured-in-place liner. Significant issues throughout the line, however, are likely to require complete repair or replacement.
Environment. Does the line run under pavement or a walkway, or under landscaping or a retaining wall? In situations like these, homeowners may prefer a trenchless option if it is available and suitable.
Financial considerations. Sewer repair and replacement can be one of the more expensive investments a homeowner can make, running into the tens of thousands of dollars. When there are multiple repair options available for a given problem, the cost of each can factor into the final decision.
Time. How long does a solution have to last in a given situation? This is often related to financial considerations. When there is a root invasion, for example, some homeowners may choose to simply have it removed, knowing that it will come back within the year but willing to put off a more permanent repair until later. Similarly, a mechanical descale may add another ten years of life to the line, while a full CIPP lining could last fifty years for only double the cost, but the cheaper solution may be a better choice for the homeowner at the moment.
Ultimately, if you need your sewer repaired, your best bet is to have your sewer inspected by a proven plumber who has long experience diagnosing and solving sewer problems, then get estimates for all of the methods that are suitable for your specific sewer line problems. Take into account your environment, your time horizon, and your financial needs (including whether your plumber offers financing), and then make the decision that best fulfills those factors while providing a free-flowing pipe to carry sewage and other debris away from your home.
About the Author: Hendrik Vandepoll is a 30+ year Master Plumber, and co-owner and Field Manager of Service Force Plumbing. He has been widely consulted about plumbing issues for national publications, including BobVila.com, USA Today, and Martha Stewart.com.
