What Is Necessary For Manhole Rehabilitation Success? Correct Application, Use Of Manhole Rehab Technologies

By Gerhard “Gerry” P. Muenchmeyer, P.E., NASSCO Technical Director | October 2011, Vol. 66 No. 10

Due to the various types of materials used to construct a manhole, it is not uncommon, for a customer to require that multiple rehabilitation techniques be applied to properly repair or renew an existing manhole.

It is important to understand that no single product fits all rehabilitation needs. Not every product is compatible with another, different manhole products require specific structure preparation requirements, and adhesion characteristics will vary for different products. Also, quality assurance is a must, and testing should be performed for all products.

The questions that arise frequently, from customers, are: which system works best under given conditions and how long will it last? Most products and technology systems have verifiable applications and longevity histories and have been proven effective over time for rehabilitating manholes. When the results do not meet expectations, customer confidence, in manhole rehabilitation technologies and products can diminish. Was the wrong product installed or improperly applied? Was the structure prepared incorrectly for long-term product performance? Was the applicator properly trained? What should be changed to ensure long term performance?

The initial step in choosing the right technology is to identify all of the existing manhole defects and defining the extent of rehabilitation required to achieve the customer’s requirements. Is the application for structural reconstruction, for corrosion protection, to stop leakage from entering the system through the manhole components or a combination of all? Once the need is identified an evaluation of available technologies can be undertaken to determine which product will do the job at the most competitive cost.

Several industry professionals, provided input for this article, including William Shook of APM/Permaform, Lee Haessig of Cretex Specialty Products, Larry Kiest of LMK Enterprises, Chip Johnson of Sprayroq and Jane Warren of Warren Environmental.

A series of key question were asked of these industry professionals.

For what type of structures is your system best applicable?

Shook: Because manholes suffer from a variety of problems, we offer multiple solutions, including Permacast structural cement liner, Permaform no dig replacement system, Cor+Gard 100 percent solid epoxy coatings, Cor+Roq structural epoxy, Conshield additive to Permacast, Permaform CIPP liner, I&I Barrier plastic chimney liner, and Cor+Flex and Cor+Seal flexible urethane sealants.

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