Trenchless Sewer Pipe Replacement

Traditional excavation is a high-impact way to do sewer pipe repair or replacement in Pittsburgh. For some problems, it’s the only option. But why dig if you don’t have to? Trenchless Sewer pipe replacement/repair uses the latest technology. It helps to reinforce your old damaged sewer pipe with durable modern plastic pipes. This noninvasive method typically uses just one entry point. And it can certainly help you avoid the disruption and costs associated with digging long trenches in your yard. This method usually takes no more than one to two days max!

Traditional trenching can take much longer.  And with traditional trenching, you’re oftentimes forced to pay to dig up the street in front of your home. You could be responsible for the traffic to be rerouted and for repairs to any city/borough-owned property or main sewer lines.  This can range from a few thousand to several thousand dollars. Trenchless methods for homes have been around for about 15 years, but many homeowners are not aware of the option. The most common types of trenchless sewer line replacement are pipe lining and pipe bursting.

What is Pipelining?

A pipe liner, also known as “cured-in-place pipe,” is a flexible tube coated with a resin that is blown or pulled into the damaged pipe and then inflated. In time, the resin hardens, creating a pipe within a pipe that is jointless and corrosion-resistant.  The lining will reduce the diameter of the lateral pipe, which connects the home to the main sewer line, by about a quarter of an inch, but should not affect its ability to get the waste out of your home.  Pipelining typically involves digging just one access hole.

And Pipe Bursting?

Pipelining might not be possible if the damaged pipe has joints or has collapsed. But the “pipe bursting method” can still be used on a collapsed lateral if there’s room to drag a cable through the old pipe.  Then a new pipe can be pulled through the old, damaged one, while simultaneously fracturing the old pipe outward.  This trenchless repair method requires making small access holes where the damaged pipe starts and ends; then, again, pulling a new pipe through the existing pipe which bursts the old pipe into pieces while simultaneously laying a new pipe.

A more detailed description shows that a torpedo-shaped metal bursting head is attached to a steel cable. This cable is pulled through the sewer line in order to burst the pipe.  The existing line becomes a conduit through which to pull the new pipe. The cable end is connected to a bursting head.  The new pipe is attached to the head.  The bursting head breaks the existing pipe and pushes it out of the way. This allows for the new new pipe to be pulled through. The new pipe is the same inside diameter as the old.  If required, it’s even possible to increase the size of the pipe.  Very little damage is caused to the new pipe in this process.  Usually, just some light scratches.

The Takeaway?

Pipe bursting and lining are mostly equally durable.  However, costs for trenchless replacement vary, depending on material prices, soil type and how deep the sewers are buried. Trenchless options can cost upwards of 30 percent more than conventional digging in some cases, but can still be more cost-effective because you’re not spending thousands of dollars on additional restorative work.  Pipe bursting or lining can be the most cost-effective and least disruptive way to go if found to be suitable for the situation.

The Trenchless Sewer Pipe Liner Repair

Step One

A camera sewer inspection is done to diagnose the problem and develop a clear plan for the work that needs to be completed. This video inspection allows the size of pipe and condition to be seen prior to starting any work.

Step Two

The pipe is accessed from its shallowest point. Once the scope of the repair is determined, the pipe is completely cleaned with both a hydro-jetter and a mechanical snake. Then a new resin coated liner is inserted into the host pipe and left to cure.

Step Three

After the pipe has fully cured, the new liner is inspected again to ensure free flow all the way to the city or borough main. Once the camera sewer inspection is complete, the pipeline is returned to service and can be used right away.

Depending on where you live and the condition and configuration of your pipes, trenching might be the best option.  You should talk to a reputable, licensed plumber and sewer line professional, like Proudfoot Plumbing, Heating, and Air about what would work best for your situation.

The Risks

City and borough engineers/inspectors have warned that this type of installation method might not pass inspection if water pools in a low spot in the line.  Because the new line uses the old line as a conduit, this is a possibility. On trenchless systems, changes in direction (deflection, belly, sag) pose a significant concern. An experienced installer should know what deflections in the existing line can be removed.  It depends on the degree of deflection and the soil conditions.  If the soil is predominantly sand, many deflections can be removed.  But, if the soil is less forgiving, such as shale, deflections may not be able to be removed.

Another issue could be the close proximity of other utilities.  As the bursting head passes through the pipe, it splits the existing pipe and forces it outward as the new pipe is pulled through.  If there are utilities close enough, the existing pipe being pushed outward can damage them.  Water lines can be cut and gas leaks can result.  Contractors should locate all utility crossings as well as close parallel utilities to determine if there is adequate room for this type of installation.

Let Proudfoot Help

With this in mind, anyone considering trenchless sewer replacement should verify that the contractor has significant experience doing it and has been trained by both the trenchless equipment manufacturer and the pipe material manufacturer.  Again, Proudfoot Plumbing, Heating and Air has expertise with this type of work and has the necessary experience for doing this type of repair quickly and to the customer’s satisfaction.  Please give us a call at 1-412-461-2198 or contact us. We will be glad to help out and/or make recommendations for you on the repair or installation of your trenchless sewer pipe replacement.

For an animated view of how the trenchless sewer replacement system works, go to this YouTube video.