Introduction

Over time, underground pipes begin to deteriorate due to factors like aging, tree roots, mineral deposits, and acidic soil conditions. This deterioration can lead to serious issues like sinkholes, flooding, and sewage backups. Eventually, homeowners have to make the difficult decision to repair or replace damaged pipes.

Traditionally, repairing or replacing pipes required significant excavation work to access the pipes. Crews would have to dig deep trenches, replace the damaged section of pipe, and then refill the trenches. This process was extremely labor-intensive, time-consuming, and costly. It also caused major disruptions to landscaping and driveways.

In recent decades, a new pipe repair method has emerged that provides a minimally invasive alternative – pipe relining. Also known as cured-in-place pipe (CIPP) lining, this modern technique involves inserting a resin-impregnated liner into the existing pipe and curing it in place without excavation. The liner is molded to the contour of the pipe and hardens to form a new pipe within the old pipe.

Pipe relining has gained widespread popularity due to its many potential advantages over traditional excavation methods. But is pipe relining right for every homeowner’s needs and budget? In this comprehensive guide, we will explore the ins and outs of pipe relining so you can determine if it is worth it for your specific repair situation.

Understanding Pipe Deterioration

Before discussing repair options, it’s important to understand what causes pipes to deteriorate over time. Pipes are typically made of materials like clay, concrete, PVC, or cast iron that degrade when exposed to certain environmental elements underground.

Tree roots are a major culprit, as they can penetrate pipes looking for water sources. Mineral deposits from hard water or soil conditions can build up inside pipes, restricting flow. Acidic soil or groundwater can corrode unprotected metal pipes. Over many years of exposure, these factors weaken pipes through cracking, crushing, offset joints, and sagging.

Deteriorating pipes not only compromise your drainage and plumbing systems but can also damage property if left untreated. Sinkholes, flooding basements or yards, and sewage backups are all risks of deteriorated pipes that homeowners aim to avoid with timely repairs or replacements. Regular maintenance through cleaning and inspections can help catch small issues before they escalate into expensive nightmares.

Traditional Pipe Excavation and Replacement

For decades, the standard method for fixing severely deteriorated or blocked pipes involved digging them up for replacement or repair. Crews would use backhoes and other heavy machinery to excavate a trench alongside the damaged section of pipe.

This process required removing huge volumes of soil, which was no small feat on its own. The exposed pipes could then be accessed for repair work like broken section replacement or joint resealing. New pipes were typically installed by hand with the help of some power tools.

Once the work was complete, the trench would need to be thoroughly compacted before refilling it with the excavated soil and restoring any disturbed landscaping or hardscaping like driveways. These projects often spanned multiple days or weeks depending on the extent of the work.

While effective for the most seriously damaged pipes, the traditional excavation method presented several major drawbacks:

• Time-consuming: Trenching, accessing pipes, repairs, and restoring surfaces took significant hours of labor over multiple days.
• Labor-intensive: Deep trenches required many workers to safely access and work on buried pipes.
• Costly: Labor, trenching machinery, landscaping restoration, and traffic control all contributed to high project costs.
• Disruptive: Excavations tore up yards, damaged landscaping/hardscaping, and blocked accesses for weeks.
• Risky: Trenches posed dangers to workers and could potentially compromise surrounding structures.

For these reasons, traditional excavation repairs posed major headaches for homeowners and contractors alike. There had to be a better solution.

Evolution of Pipe Relining Technology

In the 1970s, trenchless sewer technologies began emerging in Europe that would revolutionize underground piping repairs. Cured-in-place pipe (CIPP) lining involved inserting a flexible resin-impregnated felt tube into an existing pipe from access points like manholes.

The liner would then be inflated to fit the inside contour of the pipe using air pressure or water. A resin adhesive was cured using hot water, steam, or UV light to harden the liner into a brand new pipe within the old pipe. Early felt liners had issues with flexibility and strength but innovations continued improving the process and materials.

In the U.S., the first commercially viable pipe relining became available in the 1980s and used UV light curing resins. Further developments incorporated tighter weaves, fiberglass components, and stronger epoxy resins into the lining tubes. New advancing techniques included “pull-in” and “folded and drawn” insertions without full pipe excavation.

Today’s advanced CIPP liners provide structural equivalency and even improvements to replaced cast iron or clay pipes. Fully robots and closed-circuit camera inspections ensure precise installations. A variety of lining materials and proprietary processes suit almost any pipe composition from small service laterals to huge trunk sewers.

How Pipe Relining Works

Before starting a pipe relining project, the contractor performs a camera inspection of the pipe to analyze the severity and location of the damage. The pipe is then cleaned using high-pressure water jets to remove debris, scale, and obstructions.

With the preliminaries complete, the actual relining process takes place. A resin-impregnated felt tube is manufactured to the exact diameter and length needed based on the earlier inspection. One end of this liner is connected to an inversion head or pull line at an entrance access point like a cleanout or manhole.

Modern pipe relining relies on one of a few insertion techniques:

• Inversion or Pull-In Method: Air pressure or water inversion forces the liner inside-out through the damaged pipe.
• Pull-In Method: The liner is manually pulled into position using a cable attached to the leading edge.
• Fold-and-Pull Method: A folded liner is guided into place in sections and joined by robotic cutters and sealers.

Once fully inserted, the liner material takes the exact shape of the host pipe interior. Pressurized water, steam, or ultraviolet light then cures the resin impregnation, hardening the liner into place as a brand new “pipe within a pipe”. The cured liner seals cracks, rejoins joints, and structurally restores the entire line.

Key Benefits of Pipe Relining

With its trenchless approach, pipe relining eliminates many of the challenges posed by traditional excavation and offers these significant benefits:

• Minimally invasive: No large trenches mean little yard or driveway damage versus full excavation.
• Fast installation: Relining takes hours versus weeks for digging and pipe replacement.
• Structural upgrading: Modern lining materials strengthen pipes beyond their original construction.
• Cost-effectiveness: Saves huge labor costs over excavation despite higher material costs.
• Durability: Properly installed liners last 50+ years versus 20-30 years on average for replaced pipes.
• Versatility: Applicable to virtually any pipe material including sewer, storm, pressure, and irrigation lines.
• Low risk: Bypasses cave-in dangers and potential structural compromising from deep digs.
• Environmental friendly: Less CO2 emissions, water usage, and soil disturbance than digging projects.

For these reasons, properly selected pipe relining offers tremendous advantages that can outweigh higher material costs compared to excavation repairs. The reduced disturbances to property features and residents’ schedules are also major selling points.

Choosing the Right Pipe Lining System

While cured-in-place pipe (CIPP) lining is the most popular trenchless solution, different pipe characteristics call for variations in relining materials and processes. Choosing the optimal system depends on factors like:

• Pipe composition: Clay, concrete, plastic, metal compositions affect resin compatibility.
• Pipe diameter: Small 2-inch laterals require different materials than huge trunk sewers.
• Existing condition: Severity of damage, joint locations, bends/offsets are considerations.
• Soil chemistry: Moisture levels, minerals present influence material degradation rates.
• Intended usage: Potable water, irrigation, and high-pressure applications narrow material options.

Common pipe lining systems include:

• Felt tubes: Dense fiberglass mats for push/pull installations but weak bends/joints.
• Non-woven geomembranes: Highly flexible, resin-impervious membranes suitable for bends/joints.
• Polyester felt composites: Strong with tight weaves, accommodate minor obstructions.
• Spiral-wound liners: Continuous pre-wound tube provides tight seals around bends/branches.

An experienced relining contractor thoroughly assesses each project to specify the engineered material and process optimized for the existing pipe characteristics. This ensures a long-lasting, structurally sound repair.

When is Pipe Relining Not the Solution?

While pipe relining offers advantages over excavation in many cases, it is not always the best or only solution for severely deteriorated pipes. Some limitations to consider include:

• Pipe condition: Relining works best on pipes with minor defects like small cracks or joint offsets. Significant degradation requiring major reconstruction may still call for excavation.
• Pipe access: Protruding, disconnected or collapsed pipe sections prevent liner insertion. Digging may be needed to re-join sections first.
• Obstructions: Tree roots, mineral deposits, joint failures could block the liner’s passage requiring excavation to remove obstacles.
• Small lateral size: Very narrow pipes under 2 inches often cannot accommodate insertion/inflation of a liner bladder.
• Intersection complexity: Multiple tight bends, wyes or tees may impede proper liner placement requiring a hybrid repair approach.
• Material composition: Some very brittle or heavily corroded pipes made of clay, brick or delicate metal corrode too severely for relining alone.
• Drainage application: Lines carrying stormwater or irrigation demand different strength characteristics than sewer lines, which impacts material selection.

In cases of major blockages, collapsed pipe sections, or where the host pipe has exceeded its design life, complete replacement through excavation will deliver a more durable repair. Careful pre-inspection and a reliable contractor’s expertise determine the optimal solution.

Other Trenchless Repair Options

While pipe relining has become the dominant trenchless technology, alternatives exist that may suit special site conditions or damage types better in some cases:

• Pipe bursting involves pulling a cone-shaped burster and replacement pipe through the failed line. Best for brittle pipes needing full reconstruction.
• Pipe joining repairs leaking or offset joints using robotic cutters and sealers without full-pipe access from within.
• Spot repair trenchlessly replaces small collapsed sections by winching replacement tube segments into place.
• Sliplining runs a new, larger carrier pipe inside an existing line using either jointed or continuous pipes pulled into the host.
• Close-fit lining relies on a replacement tube that is winched or inflated tightly against the host pipe interior, providing minimal clearance.

An experienced assessment evaluates the best minimal-impact approach tailored to the specific site and failure mode. Combining methods may also deliver optimum structural and cost benefits in some repair scenarios.

Additional Considerations

Beyond technical pipe condition factors, other considerations impact the choice between traditional excavation and modern trenchless repairs:

• Project timing – Speed of relining suits urgent repairs while excavation requires more planning for disruptions.
• Access/traffic – Road/alley closures, right-of-way issues influence feasibility of open-cut excavation work.
• Property impact – Relining protects landscaping/hardscapes much better than digging when possible.
• Future maintenance – Trenchless repairs permit internal inspections and jetting without subsequent disturbances.
• Cost factors – While materials usually cost more, overall project outlay factors in avoided land/access mitigations.
• Warranties – Modern liners come with 50-year structural/performance guarantees backing the major investment.

A professional contractor weighs all aspects to create a customized solution maximizing long-term value and minimization of future issues for each unique project and site. Communication ensures expectations align on all sides.