Coating of New Pre-Cast Concrete Manholes

Project Description – Customer had placed an order for new, pre-cast concrete manholes. When left unprotected, Hydrogen Sulfide gases can attack the unprotected concrete, which can cause leaks, deterioration and environmental concerns. The Customer asked to have their new manholes coated, prior to them being installed. Coating pre-cast manholes prior to installation, was more cost effective and less disruptive to ongoing treatment operations.

Application - Coating of New Pre-Cast Concrete Manholes

Industry – Water/Wastewater

Contractor – Asset Owner

Problem – Concrete manholes, when in contact with hydrogen sulfide gases, would deteriorate in a short amount of time. Having manholes coated after being installed, would have resulted in exposure to H2S gases and would have resulted in a more costly and more disruptive coating process.

Solution – Prepare concrete substrate. Apply two (2) coats of Belzona 5811 Immersion Grade (available in three colors – Black, Gray and Beige). For this application, the customer chose a dark base coat (Black) and Beige topcoat, making the manhole brighter and improving visibility in the area. The “after” picture shows the manholes, inspected after 12 years of being in-service. Manhole substrate and coating were deemed to be in perfect condition.

Product Applied - Belzona 5811 Immersion Grade

Product Detail – Belzona 5811 Immersion Grade is a two-component, solvent-free coating system designed to provide protection to metallic and non-metallic surfaces, operating under immersion conditions in contact with aqueous solutions. 5811 is 100% solids, contains no VOC’s, is flexible, can be applied to virtually any surface type and is an outstanding long term coating solution.


Precast Manholes Receiving Base Coat of Belzona 5811 Immersion Grade


Precast Concrete Manholes After 12 Years of Being In-Service