It is an old tale. Sewer, water, or gas lines running under a home breaks due to roots, age, or foundational sifting. Homeowner’s insurance rarely covers the cost, so the burden falls on the shoulders of the owner to find the quickest, cheapest method of repairing.
Trenchless rehabilitation can be a viable solution.
Uses of Trenchless Technology on Private Property
Most people think of trenchless technology as something only cities take advantage of to repair and rehab significant pipelines. This fact could not be further from the truth, as many repair companies use the same technology for private property owners.
Homeowners facing water, sewage or gas line issues find that trenchless methods are better suited to their needs. These techniques can be used to rehabilitate lines infiltrated by roots from trees and bushes growing on the property. Workers also use them to repair or replace pipelines broken due to age or structural settling.
Types of Trenchless Rehab
There are several types of trenchless rehabilitation options available. However, some techniques are more popular for private property than others.
Sliplining
Sliplining is one of the most popular choices to rehabilitate and repair broken utility lines on homeowner property. With this procedure, workers insert a smaller diameter pipe into the mainline. This line within a line becomes the new service pipe for the home. The old host pipe acts as a sheath offering additional protection from settling and root infiltration.
Depending on the amount of egress between the new and old pipelines, the workers may grout in between the two to fill in the excess space. However, not all sliplining projects require grouting.
For workers to use sliplining, the section of pipe must be straight. Slipliners cannot move around bends in the plumbing.
Cured-in-Place Pipe
Another popular trenchless rehabilitation method is the use of cured-in-place pipe, better known as CIPP. Like sliplining, this is a line within a line. However, instead of using a PVC or other hard pipe as the new plumbing, CIPP uses a resin-saturated fiberglass tube. The tube is inverted and pushed through the line from an upstream location. Once in place, the resin hardens creating a pipeline within a pipeline.
There are a couple of benefits to using CIPP instead of sliplining. One is there is absolutely no grouting necessary. The resin tube fits snug within the existing line with no significant gaps between them.
The second is flexibility. Sliplining is only useful on the straight pipeline. It cannot go around bends. CIPP, on the other hand, hardens after it is in place. The fiberglass tube can readily bend with the existing line, creating one solid pipe with no joints to leak.
Spot Repair
In some cases, spot repair may be the best trenchless rehabilitation option for the homeowner. This method repairs the damage at specific points in the pipe. However, for this to be a viable option, the damage must be minimal and cannot be large enough to compromise the integrity of the overall pipeline.
With spot repair, workers insert a grouting sleeve with a mechanical locking system and the core of stainless steel into the damaged pipe. Using robot technology, they guide it to the damaged area. Once in place, air expands the sleeve until the locks engage. After the grout is in place, the jacket is deflated and withdrawn. As the grout hardens, it expands filling in the cracks.
Pipe Bursting
Depending on the amount of damage to the pipe, sliplining or CIPP may not be feasible options. Homeowners may have to replace the pipeline instead of rehabilitating it. If that is the case, pipe bursting may be their best option.
Pipe bursting is precisely how it sounds. Workers insert a steel cable into the existing pipe. Attached to the cable is a bursting head. The cable pulls the head which breaks up the current line in a process known as fragmentation. A new pipeline is pulled into place behind the head. In most cases, the pieces of old pipe lodge in the surrounding soil, providing additional support for the new line. Some parts may come out in the exit trench with the head.
Pipe bursting does require a little more digging than CIPP or sliplining, as an entry trench and exit trench are necessary to run the cable and the bursting head. However, in comparison to traditional trenching methods, the amount of digging is insignificant.
Benefits of Trenchless Rehab
When it comes to trenchless rehabilitation, homeowners often look at two main benefits, time and money. Trenchless methods usually take far less time to complete than traditional trenching procedures. Because there is little to no digging, crews can inspect the site, install new plumbing, and be complete with city inspections within three to four days. Depending on the location of the cracked pipe, traditional methods can take one to three weeks. (Also see "Are Construction Traffic Diversions Necessary for Trenchless Projects?.")
In addition to completing the job quicker, they often come out cheaper. While the cost per foot may be about the same or slightly more, running from $80 to $250 for trenchless versus $50 to $250 for traditional, there are other costs to consider. Traditional trenching methods do not include the cost of replacing landscaping or repaving driveways, sidewalks, or foundations. These costs can add an addition $20,000 to your repair bill. (See "Studies Claim the Trenchless Construction Cost Comparison is Massive.")
Trenchless rehabilitation only minorly disturbs your landscaping and can run underneath concrete without destroying it. The total costs end up being closer to $6,000 to $12,000 instead of $4,000 to $13,000 plus the cost of landscaping and concrete.
With many options to choose from, there is probably a trenchless rehabilitation method that works best for most homeowner problems. A local plumber can go over all your options and help you pick the right one.