When manhole rehabilitation is required it is important to note the conditions of the manhole before deciding which method would work best.
A camera is used to survey the condition and allows the contractors to determine the nature of the problem.Some of the conditions that affect the decision include the gasses present in the structure,sewer flow,and oxygen levels.
When beginning manhole rehabilitation it is necessary to cease water flow through the manhole.If using an adhesion paste,the manhole needs to be either sand blasted or pressure washed before the paste is applied.
Grouting the manhole is another option.Like using the epoxy, the manhole must be cleaned prior to repair,however,there are a variety of chemically mixed formulas that must be matched with the surrounding soil conditions.This process can be completed within a few hours.
Manhole Lining is a method used when the manhole requires structural reinforcement,needs protection from seepage of groundwater,or needs protection from corrosive gases.
After the inside of the manhole has been repaired,the manhole itself needs to be replaced. This is done by completely removing the current manhole and replacing it with a new one.