Why Are Fiberglass Manholes Preferred Over Cast Iron Manholes?


Manholes are a big part of a city/town life. A manhole isn’t just a hole usually with a flash cover through which a person enters to check the underground structure. It is a part of the sewage system of a city, for instance, that carries solid and liquid waste materials and wastewater. Hence, manholes allow to inspect and maintain the sewage system that, in turn, keeps the city clean.

Until recently, cast iron manholes were installed all over the world, maybe those manholes are still being installed in some parts of it that weigh around 100-200 lbs per piece. But, the growing inconsistencies of the cast iron manholes have paved the way for an innovative product the fiberglass manhole. It means fiberglass manholes have something unique that befits the demand of the current era. Visit the page http://fibertechinc.net/rhino-manholes/manholes-ultimate-resource/ to know more here.

Key areas of fiberglass manholes:

Lightweight manhole

This is palpably the best part of installing the fiberglass manholes. According to an estimate, the average weight of a fiberglass manhole may vary between 28 lbs to 83 lbs. In between these two extremes, there are seven variants available in the market. It means you have a  range of fiberglass manholes to choose from bespoke to your need. On the contrary, a cast iron manhole is very heavy compared and thus, it isn’t easy to handle and maintain.   

Avoiding thefts

This might sound awkward but true that cast iron manholes are vulnerable to theft as they have scrap value. On the flip side, fiberglass manholes do not have any scrap value and thus, they are safe for installation in any part of your town/city or at each house.

Secure manholes

The cast iron manhole lid is loosely fit that gives passage for the sewage to come out wherever the sewage system develops a clog. On top of it, it has no locking system whereas fiberglass manholes have a downward locking system that firmly holds the lid to its place.  

Corrosive resistant

Cast iron manholes fall flat to corrosion. Having said that, we mean, it isn’t corrosive resistant. As a matter of fact, these manholes start waning away soon due to the chemical reaction of oxygen with iron. What you see here is rust formation around the cast iron manholes. But, fiberglass manholes are corrosive resistant and thus, offer flawless service for many years. According to a study, a fiberglass manhole usually lasts more than 30 years.   


You will be happy to know that compared to the cast iron manhole, a fiberglass manhole is less resistant to radio signals. Hence, a fiberglass manhole is congenial to AMR (automatic meter reading) and SCADA (supervisory control and data acquisition) systems that help to track the sewage level and others. Besides, fiberglass manholes are nonconductive to telco and electricity operations that is beneficial to them.    

Low maintenance cost

Compared to cast iron manholes, the average cost of maintaining fiberglass manholes is low.

Likewise, based on the area of a city or town you live, you will find many such benefits of installing fiberglass manholes.

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