Understanding The Benefits Of Trenchless Drain Repair

Problems with drain systems around your home can often be a bit of a headache, particularly where the drain shares a common border with your neighbor's property. Not only will you be bickering over who picks up the bill, but also whose yard becomes the construction site for extensive trenching works in order to allow contractors to fix the problem. If the drainpipe hasn't completely collapsed, you may be in luck due to the emergence of trenchless draining. 

An Overview of Trenchless Drain Repair

Trenchless drain repair, also known as "no-dig" or "relining," is the quickest and most cost-effective way to repair drains and sewers which has become available due to advancements in modern technology. Additionally, trenchless solutions are much less intrusive than more traditional methods, meaning much less disruption is caused to the surrounding area. This means that trenchless repair isn't only best for you, it's also best for the environment. 

How the Method Actually Works

Trenchless drain repair works by inserting a liner loaded with resin into the drain or sewer. As this liner is pushed in to the drain, the operator turns the liner inside out and forces it through using pressurized air. Pressurized water may also be used for this purpose however it is a more difficult procedure. 

After the liner is fully inserted, the material bonds to the inner surface of the pipe. The liner is then left untouched until the resin has hardened, creating a "dummy pipe" within the drain that restores the structural integrity of the damaged surface. 

With relining, there is no "one size fits all" solution. Rather, each project demands a unique design and requires decisions to be made regarding: 

  • Type of liner used. 
  • Grade of resin used for bonding. 
  • Method of curing or hardening the resin. 
  • Solutions for re-opening the sewer or drain. 

The above for design criteria are mainly based on the geometry of the damaged line and the severity of the problem, however the operator will take a wide range of factors into consideration before proposing a solution. 

Advancements in Trenchless Technology

The reason trenchless drain repair is quickly becoming recognized as the best solution is due to advancements in technology. Your contractor may take a number of approaches, however below are three of the most common and effective techniques used. 

Ultraviolet Light

Contractors typically use UV light in order to cure or harden the lining, allowing it to bond with the damaged line. There are two main reasons for this: 

  • Speed: Using UV light to harden the bonding material is much faster than traditional approaches, with speeds less than one meter per minute. This means a 50 meter stretch of pipe will be fully bonded in under one hour! 
  • Durability: Lining that has been cured by UV light is extremely durable, with typical design lives of over 100 years. 

Lateral Rehabilitation (Top Hats)

Top hats (aptly named so because of their appearance) are used in order to provide seals between the main pipeline and its lateral connections. Typically, these consist of resin-loaded, fiberglass laminates that wrap around the circumference of the main line. This effectively seals the connection, whilst allowing the smooth flow of water between the lateral pipeline and main sewer. 


Patch (or "spot") liners are great for covering localized cracks and fractures, as well as hiding displaced joints and holes. Patch liners are typically made of fiber-glass, and are maneuvered into position using an inflatable packer. Patch liners are a great (and very cost-effective!) way for repairing smaller problems before they develop into much larger issues. 

Trenchless draining is a cost-effective, non-intrusive method that allows contractors to solve the problem without disrupting your yard and driveway. As mentioned, it is typically only suitable for small problems, however you should discuss this with your contractor who will be able to assess the problem and offer professional advice.