Beyond the Bandage

Cured-in-place-pipe (CIPP) has been a transformative technology in the plumbing and wastewater industry, enabling trenchless repair of aging pipe with minimal disruption. It’s often an option for municipalities, contractors and property owners looking for a quick fix.

However, like all technologies, CIPP has its strengths and limitations. While CIPP can be effective in certain applications, it’s important to recognize the downsides, especially when considering installation challenges, long-term durability, structural integrity and costs compared to alternatives.

Take it from me, a former commercial service plumbing manager who offered a variety of trenchless replacement options until unexpected installation challenges and cost considerations forced a change in sales strategy regarding sewer rehabilitations.

From a service plumber’s standpoint, any trenchless technology offers instant appeal. CIPP is a process that creates a new pipe within an existing one by installing a resin-saturated liner. The liner is then cured to form a seamless pipe. Jobs are quicker, less invasive and offer higher gross margins for the contractor, as minimal excavation is required. This method, however, is far from foolproof and when mistakes occur, the consequences can be costly.

While CIPP lining works well for certain applications, it does not solve larger systematic issues. For example, if the soil outside the pipe has settled or other parts of the sewer system are about to fail, simply lining the pipe treats the symptoms only, not the root cause. 

Lining a pipe doesn’t stop corrosion in pipe it merely covers it, like putting a bandage on a broken bone. Trapped moisture between the liner and pipe can accelerate corrosion, leading to hidden problems that may surface years later. This limitation often creates a false sense of security for property owners, backfiring when subsequent failures occur in untreated sections.

Reputation at risk

Let me set the scene. It’s early February 2021 in Texas. We scheduled a building shutdown for several essential businesses during the COVID-19 pandemic to perform a 300-foot pipeliner job on a 6-inch mainline. The shutdown days were planned strategically with a restaurant, dialysis center, urgent care and several other retail spaces. 

The day before starting the job, “Snowmageddon” arrived in North Texas — a deep freeze with approximately 3 inches of ice topped with snow and freezing temperatures. This was a service plumber’s paradox: enough freeze breaks to hit revenue goals for the entire fiscal year within a singular month, but an avalanche of a workload. We stuck with the schedule, hoping that the CIPP job would go smoothly. 

Well, in the service world, when you need jobs to go efficiently, they tend to turn into nightmare scenarios, which is exactly what occurred. During our post-camera inspection, we noticed folds, tears and insufficient application of the liner. The failure led to emergency tunnel excavations and repairs. This inconvenienced the owner of the building as additional costs were incurred due to the failure and disrupted business as a whole, affecting subcontractors, tenants and other customers. 

This experience — and others like it — was the final straw that forced us to reconsider using CIPP as part of our repertoire.

A failed liner not only compromises the structural integrity of the sewer system; it also places the contractor’s reputation at risk. Relationships with customers can be hindered if a liner failure results in additional downtime, unplanned excavation, or repeated rehabilitation. For plumbers, the stakes are high — one unexpected mistake in the installation process can lead to costly rework and insurance claims. 

Exposure to liability

I had the pleasure of speaking with Roger Ross, master plumber of 30 years and former CEO and owner of Restaurant Plumbing in Lake Forest, California. Ross is one of the pioneers in California’s pipelining industry and understands CIPP as a two-sided approach to replacing or refurbishing sewer lines. 

“Pipelining is a good option for repairs beneath busy city streets or under historical areas for preservation purposes,” he says. Ross views pipelining repairs more as spot repairs and less for underneath commercial buildings. “The perfect scenario for a liner is only one change of direction — one-quarter bend or eight bend — but when you have several fittings back-to-back, it’s tough for a liner to make turns, often getting stuck and forcing excavation,” he adds. 

Ross notes that while cabling a CIPP-lined sewer, it is possible to hook and remove the seam tape of the felt tube, ultimately compromising the liner. As a former business owner, evaluating risk exposure was important to the health of his business. “Companies expose themselves to liability when lining an entire system,” he explains. “When a liner goes right, you look like the hero, but when it fails, you’ve dug yourself a hole that is tough to get out of.” 

To avoid that liability and inevitable risk exposure, Ross says: “When you fully replace with cast iron, PVC or ABS, you know the starting and ending points within a system. But with CIPP, you never know what issues will arise.”

Full replacement is the gold standard 

When designing, an engineer prioritizes structural reliability, long-term performance and resolving the origin of the problem. The advantages of CIPP should be weighed against the possible risks of generating more problems with the existing system. 

Pipeliners are not stand-alone structures; they depend on the stability of the host pipe for load-carrying capacity, especially with high traffic loads. If the host pipe degrades or collapses, the liner will fail to provide support. These limitations make CIPP unsuitable for sanitary systems in advanced stages of corrosion or excessive deformation. The life span of a lined pipe depends on the success of the installation and how well the system is maintained. 

From an engineering perspective, full replacement remains the gold standard for sanitary sewer rehabilitation. It may require slightly higher upfront costs, but the benefits in terms of durability and long-term performance are worth the investment. 

Several years following the Snowmageddon liner job, I was presented a bid opportunity very similar in scope of work. A proposal was requested for fully repiping the entire underground sewer system of an office building, approximately 300 feet in length. The cost differential between the “snowmageddon” job versus this office complex was minimal. For 17% more, the office building received a complete replacement of the mainline and branch lines — from city tap to closet flanges. 

The value derived from the additional 17% costs includes a new structurally sound and reliable sewer system, a 10-year warranty and peace of mind. Compared to the liner job, which offered a 1-year warranty and not a single stick of new pipe was installed!

While CIPP offers benefits in terms of speed and less surface disruption, its limitations exclude it as a one-size-fits-all solution. Contractors, engineers and owners alike must carefully consider the risk versus reward before selecting a rehabilitation method for sanitary sewers. 

For commercial applications, full pipe replacement remains the preferred choice, offering peace of mind to all parties involved. CIPP is more aptly suited for a temporary solution or a spot repair in areas difficult to access.

Ultimately, the decision on sanitary sewer fixes comes down to balancing quality and durability over cost and convenience. Prioritizing risk over reward protects the reputations and trust of those in the plumbing industry. 

John Marc Shelly is a technical services regional manager for McWane Plumbing Group, overseeing operations across the Western United States. With more than seven years of experience in the plumbing industry, he has developed expertise in sales, commercial operations and project management. With extensive hands-on knowledge and having accumulated journeyman hours in the field, he has a deep understanding of plumbing systems and services. 

A new approach to epoxy: DuRa Pipe

When considering new construction or sewer rehabilitation piping materials for your next project, consider enhanced epoxy-coated, cast-iron pipe by Tyler Pipe and AB&I Foundry: DuRa Pipe. Applied to cast-iron soil pipe and fittings made in the United States, DuRa Pipe is well-suited for aggressive drain, waste and vent applications where greater performance is required. 

Standard cast iron pipe and fittings perform exceptionally well in most applications. However, DuRa Pipe offers significant advantages for aggressive applications and installations such as commercial kitchens, medical office buildings, hospitals, soda fountains, casinos, seasonal occupancy buildings, low-flow fixture restrooms and any area exposed to chemicals from pH 2 to pH 12. 

DuRa Pipe is coated with a two-component, solvent-free epoxy that provides the same additional protection against corrosive environments; fittings are coated using a fusion-bonded epoxy process. The average mil thickness is 11 to 18 mils inside and outside while the fittings average 11-16 mil thickness inside and outside.