
How to Perform Cost-Effective Manhole Rehabilitation
Manholes are vital components of sewer systems, yet they often face deterioration due to microbiologically influenced corrosion (MIC). To address these challenges, a cementitious substrate repair material application followed by an epoxy lining at an average 125 mils thickness will create a barrier impervious to hydrogen sulfide – the main culprit behind MIC. This method, as opposed to a multi-coat application of an epoxy, results in a smoother surface with an added benefit of cost-efficiency. The steps below require less downtime and less labor and material costs.
Step 1: Assess Manhole Condition
Begin with a thorough inspection to identify inflow, infiltration, corrosion, or structural damage. This will guide the necessary repairs and proper material selection.
Step 2: Surface Preparation
Eliminate debris and contaminants with abrasive blasting, shotblasting, or water jetting to ensure a pristine surface for the repair material to adhere to. The surface texture should resemble an ICRI CSP profile between 4 and 6 and have a minimum pH of 8.
Step 3: Applying Cementitious Substrate Repair
Apply the appropriate cementitious substrate repair material to fills cracks, patch holes, and restore structural integrity. Follow manufacturer guidelines for mixing and application for optimal results.
Step 4: Epoxy Lining System Application
Once the substrate repair material has cured, apply a 100% solids epoxy lining system to the manhole’s interior ensuring a coverage of 125 mils thickness. This epoxy lining creates a seamless barrier against water infiltration, corrosion, and deterioration that will extend the service life for years to come.
Manhole rehabilitation is integral to maintaining sewer system functionality and integrity. By employing a cost-efficient approach involving cementitious substrate repair followed by a 125 mils epoxy lining system, professionals can save resources while ensuring infrastructure longevity. Regular inspections and timely rehabilitation mitigate costly repairs and service disruptions.