Manhole Renewal

Manhole Renewal Applications

Dependent upon customer requirements and/or preferences, Granite Inliner performs manhole renewal installations using both Cured-In-Place Manhole (CIPMH) and a variety of cementitious, epoxy-based applications.

In addition to renewal capabilities, Granite Inliner provides extensive manhole inspections, which is the first step in determining the best application(s) for improving sewer system performance. These comprehensive inspections provide a concise evaluation of the state of the structure, spanning from the cover/frame to the bench and base. Our key manhole renewal superintendents have been certified through the NASSCO Inspector Training and Certification Program.

CIPMH Applications

Engineered for a service life of 50 years, Cured-in-Place Manhole Lining (CIPMH) restores structural integrity,eliminating infiltration and inflow. Our CIPMH installations produce a cured-in-place seal that resists freeze and thaw conditions and creates a watertight, corrosion-resistant structural lining.

CIPMH Installation and Timing
Our CIPMH liners are customized to fit manholes and related structures constructed of brick and mortar, pre-cast concrete or block.

Granite Inliner crews can complete preparation and installation in the same day, eliminating lead time for ordering materials. Our crews routinely complete three to seven installations per day/per crew. The liner will cure under ambient temperature and pressure in one to two hours.

Cementitious Applications

Granite Inliner project teams apply cementitious coatings as specified by our customers, based
upon acute conditions of concrete deterioration, usually in the range of .5” to 2”. Cementitious coatings are a good option for structure renewal projects where bypass pumping or
flow control is limited.

Cementitious Installation and Timing

Cementitious coatings apply well on damp surfaces and in the presence of moisture in the atmosphere. They typically require minimal surface preparation beyond high pressure and/or detergent cleaning.

These high-strength formulations allow a monolithic .5” to 3” one-pass spray application that restores structural integrity to deteriorating manholes and provides apermanent seal against corrosion, infiltration and exfiltration.

Cementitious coatings are spray-applied, pumped and troweled, or spin-cast. As with other renewal methods, cementitious coating types are dependent upon the degree of damage and deterioration, structure dimensions, system requirements, and location.

Epoxies by Raven Lining Systems

Granite Inliner also provides epoxy-based solutions by Raven Lining Systems. Raven’s epoxy products offer great advantages in adhesion, chemical resistance and structural renewal strength.

Epoxy Installation and Timing

Prior to applying the epoxy product, the Granite Inliner team performs a visual assessment of the manhole structure, then cleans the surface using water blasting. Cracks and damaged areas are patched, and if the damage is severe, a cementitious underlay is applied. The Raven epoxy is applied with a hand-spray gun with a technique called cross-hatching, or “boxing,” to ensure even coverage and thickness. Final thickness can range from 80-125 ml or more per application.