Culvert Sliplining

What is Culvert Sliplining?

Culvert Sliplining is a method of pipe repair that has been around for decades. It is used to repair a structurally-deficient pipe, or to add more service life to an existing pipe. Much of our nation’s infrastructure is aging. For example, in the Northeast, some of the oldest infrastructure includes galvanized metal pipe and concrete/brick pipe that has been in the ground anywhere from 50 to even 100 years. Sliplining is generally a trenchless method, and involves sliding a slightly smaller pipe into the defective pipe, or “host” pipe. The insertion of the smaller pipe will effectively strengthen and repair any issues with  structural integrity and/or the infiltration of water and silts. Before this process can begin, the structural and hydraulic properties of the smaller pipe are checked to ensure it will provide sufficient support for the host pipe. Once the new pipe is inserted, bulkheads are built in the upstream and downstream ends. To fuse the pipes, grout is then injected into the annular space between the old and the new pipe.

Why Culvert Sliplining?

Municipalities and clients will often research and select culvert sliplining for their project because it checks several socioeconomic boxes. It is also a very cost-effective method for pipe repair. Some of the reasons to choose slipining include, but are not limited to:


  • Faster results. Sliplining usually does not require extensive digging or traffic detours, meaning work can begin much sooner and can be finished faster. 
  • Cost efficiency. Due to the minimal need for excavation activities, and the reduction or complete elimination of pavement work, the culvert sliplining process is a fraction of the cost of digging up and replacing old pipes.
  • Lower impact to the public. There are little-to-no traffic disturbances with sliplining, as most of the culvert rehab work can occur off the shoulder of the road. This allows for the normal flow of traffic. 
  • Easier permitting. Culvert Sliplining is generally an easier permitting process due to reduced “in-stream” work.  As culvert rehabilitation generally results in a faster project completion, it often allows the contractor to get out of the stream faster.
  • Environmentally friendly.  Aquatic life —  and sometimes even bats and other wildlife — may have built their habitats within the culverts. Because the rehabilitation process often allows the host pipe to remain in place while the culvert gets fixed, the animals will experience minimal disruption. 
  • Increased safety. The pipe repair work can usually be done off of the shoulder of the road (instead of in the roadway), which greatly reduces the risk of injury for work crews. 
  • Less impact to utilities.  While it is still important to identify surrounding utilities (just in case other work is required), most often the nearby utilities will not be disturbed since the amount of on-site digging is usually minimal. 
Sliplining Pipes together
DL VEWS sliplining at a job site

What is the lifespan of Culvert Sliplining?

Generally speaking, the lifespan of a culvert slipline design is meant to be the same as a given roadway or site, meaning the aim is a minimum 50-to-100-year lifespan. This is a consideration that is always discussed during the vetting and design phase, or during discussions with the project owner. It is important to note that design criteria, such as pH tolerance, abrasion levels, resistivity of the soils and water, live load from traffic/rail/aircraft, and dead loads (among other design factors), can affect the service life of any material. 

Superior Products

All pipe products represented by DLVEWS Inc. are fully structural and pass the high standards and requirements of even the most stringent highway requirements. All of our solutions are AASHTO and/or ASTM qualified. As an added benefit, these solutions do not rely on the condition of the host pipe or the surrounding grout for structural capacity. This means they can also be buried directly or used as standalone solutions. When owners, engineers, contractors, and developers work with DLVEWS, they can feel confident that the best hydraulic and structural options have been offered to them.

Which products does DLVEWS use for sliplining?  

In order to best serve our clients, DLVEWS represents the following products: 

  • Snap-Tite
  • Channeline
  • Weholite
  • DuroMaxx
  • Corrugated Aluminum and Aluminized Pipe
  • UltraFlo
  • Tunnel Liner Plate
  • SPR-PE (Spirally Wound Steel Reinforced HDPE)

Additional options are also offered as needed based on project scope.

Sliplining two pipes together

Sliplining Videos

Other Culvert Sliplining Information

Each site presents its own unique challenges, but DLVEWS has a solution for them all. For example, consider a site with active water that would disrupt normal culvert sliplining activities. While smaller flows can be easily accommodated while lining, we’ll set up a bypass for more significant water activity. Installers would then build bulkheads using brick and mortar or high-strength mortar. Skid rails and blocking would then be established so that the liner pipe does not float or get damaged during the installation and grouting process. Grout is then injected into the annular space. We will often recommend the use of a low-density cellular grout or lightweight cellular concrete (LDCC or LWC. This material is very pumpable, flowable, and presents a lot less buoyancy force on the liner. 


We invite you to call DLVEWS to discuss your project and the many solutions we can provide you. 



What is the service life of your liner materials, including HDPE, GRP, CMP, etc.?

The targeted service life of everything we design, and the materials we select, is at least 75 to 100 years.

What is the Manning’s coefficient of your liners?

The coefficient will vary based on the ideal material for the project. Many of our HDPE liners and GRP liners have a Manning’s of 0.009, while some of the metal plate liners can be as high as 0.035. We also offer an internally-corrugated HDPE—which has a Manning’s of 0.028–0.032 —and works well for meeting stringent aquatic life needs (which are often required by the DEP and other environmental authorities).

Should an annular space be grouted? If so, what is the best material for this?

Often, the preferred choice for annular space grouting is low-density cellular concrete (LDCC). Other materials, such as flowable fills, can be used in certain instances. The DLVEWS team can recommend the best material based on your project’s specifications, so please ask us for details.

Which types of culvert and sewer geometries can you slipline?

Almost anything! With the implementation of our Channeline GRP non-circular shapes, we can line just about any shape you can think of!

What is the minimum and maximum height of earth cover your pipe liners can sustain?

Depending on the material, typical minimum cover amounts are 1 to 2 feet. Maximum cover amounts can range from 30 feet to more than 65 feet. We will check these for you, and will determine the best material.

What’s the average lead time to obtain these materials?

If we need to order the materials, you can expect the following approximate lead times:
HDPE: 3–4 weeks
CMP: 4–6 weeks
GRP: 8–10 weeks
Please ask us for specifics when we discuss your project.

What pressure can your pipe joints sustain?

Culverts do not typically require a pressure-rated joint. Our liners are used for structures such as sanitary sewers, which may require a pressure-rated joint. In this case, our HDPE and GRP solutions have joints that can range from zero to 30psi. We invite you to discuss this with your DLVEWS representative during the design and specification process.

Can you put lateral connections back into a liner pipe?

Yes! There are several means and methods for doing this successfully.

Which lengths of liner pipe are available?

Nearly unlimited! Our longest liner to date is 1,600 linear feet. It’s a function of having the appropriate methods and installation equipment.

What can DLVEWS do for me?

We pride ourselves in offering a very hands-on approach. We will visit job sites with engineers and owners alike, will review plans and specifications, and work as a team to determine the best liner solution. Contact us any time.

To See Other Culvert Rehabilitation Methods