How Trenchless Plumbing Pipe Replacement Works   Share

by Greg Smith, Roto-Rooter of Mobile

Have you ever wondered how you would handle the need to repair a broken or damaged plumbing pipe beneath the foundation of your home? The idea of having to deal with this type of repair is certainly an alarming one. Just think of the mess – not to mention the cost – of having to dig beneath your slab foundation to get to a plumbing pipe problem. Fortunately, digging isn’t the only answer in most cases. Depending on your specific circumstances, trenchless plumbing pipe replacement just might be a viable solution.

When to Use Trenchless Plumbing Pipe Replacement
Traditional plumbing repair involves digging into the ground to get to broken or damaged pipes so that they can be repaired or replaced. Trenchless repairs techniques accomplish the same objective, but without the need for digging.

When plumbing pipes are fairly easy to get to and doing so won’t lead to foundation damage – or damage to something else like a sidewalk, tree, driveway or other surface, digging is generally the best and least expensive option. However, it’s not unusual for plumbing problems to develop in areas that cannot be easily accessed. That’s when trenchless pipe replacement becomes the most practical and cost-effective solution for homeowners.

Trenchless Pipe Replacement Methods
The two most commonly used trenchless pipe replacement methods are cured in place pipe (CIPP) and (2) pipe bursting.

Method One: CIPP
This technique may be the best solution when only one end of a broken or damaged pipe is accessible and when the diameter of the damaged pipe is at least four-inches. To make the repair, a qualified plumber will begin by placing a “sock” of fiberglass matting that has been soaked in resin and that contains an inflatable bladder into the original pipe, referred to as the host pipe. This sock will become a new pipe, housed inside of the host pipe.
Once inserted, the sock is turned inside out and the bladder is inflated. The bladder serves the purpose of keeping the sock in place while it cures for approximately four hours. Once curing is complete, the plumber removes the bladder, leaving behind a brand-new fiberglass pipe.
Method Two: Pipe Bursting
When it’s possible to get to both ends of a damaged plumbing pipe and there are no exterior obstructions, it may be possible to use the pipe bursting method for residential pipe replacement.  It’s also important to note that this technique works only with PVC, clay or cast iron pipes, or pipes made from another material that can be bursted.
To replace a broken or damaged pipe using this technique, the plumber beings by threading a three-quarter of an inch wire logging cable through the original pipe. The plumber will attach a funnel-shaped bursting head paired with a new high density polyethylene (HDPE) pipe to one end of it and places a pulling device powered by hydraulics to the other end.
Once that is done, the plumber applies brute force to pull the new pipe into place. This causes the bursting head to physically split through the damaged pipe. The pieces of the broken pipe are pushed into the surrounding dirt and a brand new HDPE pipe is pulled into position where the old pipe once was.

 Pricing Consideration
While trenchless pipe replacement can be the most cost effective option for pipes that beneath foundations or other surfaces, it is not literally cheaper than traditional excavation replacement – it actually costs about twice as much per foot. However, when you factor into the equation the cost of repairing surface damage when digging through a foundation, the savings can be significant.

About the Author
Greg Smith is President of Roto-Rooter of Mobile, Alabama. The company provides industrial, commercial and residential plumbing repair services, including video pipe inspection, throughout Mobile, Baldwin and Washington counties in Alabama.