The Triplex Liner System manufactured by McNeil Technologies is a superior manhole, pump station and culvert cured-in-place rehabilitation system. Structure preparation and liner installation can be accomplished in a few hours. Triplex manhole liners carry an unprecedented unconditional non-prorated 20-year warranty.

Our Licensees typically provide free inspections and pricing for groups of structures. Simply choose the structures you desire to rehabilitate and contact your local certified licensee to begin our pilot program.

Triplex liners are composed of layers of fiberglass and a non-porous membrane. This multi-layered system of materials supplies structural strength to the host structure and stops further infiltration. The process we go through to rehabilitate a structure is detailed.

Triplex Liners manhole rehab process


  • Every single structure is inspected and exacting measurements are recorded along with thorough field notes. We gain a complete understanding of each structure’s needs prior to a liner ever being put into production. A custom liner is then fabricated for each structure.

  • At the jobsite, the structure is high pressure cleaned and etched, (up to approx. 5,000 psi). Pipes are trimmed/grouted around as needed.

  • Benches at the bottom of the structure are rebuilt as needed and a bridge platform is placed just over the invert channel allowing for uninterrupted flow during the installation.

  • The liner is then completely saturated inside and out using our signature yellow epoxy resin and lowered into the structure.

  • Once the liner is in place, it is promptly inflated, (via an internal inflation bladder), using both steam and air pressure. The amount of air pressure exerted is in excess of hydrostatic head pressure of infiltration. (The liner will bond to a wet or dry surface.) Curing takes place in approximately one hour.

  • After curing is complete, the inflation bladder is removed, laterals are re-opened and the plywood bridge over the invert channel is removed.

  • Liner installation is complete. Total time start to finish is usually 4-6 hours. Sewage flow has continued this entire time.

McNeil Technologies produces Triplex liners for preventative or lightly deteriorated structures as well as structures that have severe deterioration and/or infiltration. Also available are Triplex liners for culverts bearing heavy traffic loads.



Severe corrosion and deterioration. This manhole is structurally unsound.



Complete restoration. Sewer manhole is now structurally sound and fresh groundwater is no longer leaking into the sewer.

For nearly 30 years we have led the effort to permanently restore tens of thousands of underground water and sewer structures. We work closely with hundreds of cities, counties and engineering firms to answer their water and sewer rehabilitation needs. If you have concerns about failing infrastructure or even new projects that you want to guarantee structural longevity, call us today.