When it comes time to repair manhole damage, choosing the right approach for the job is vital for constructing a manhole that will last for many years to come.

INSPECTION

• An inspector should always inspect the manhole before any repair is done.
• Methods may include a camera, video or light detection or ranging assessment.
• A proper inspection will reveal the condition of the manhole, which will lead to an easier decision of how it should be repaired.

MANHOLE REHABILITATION OPTIONS

• Manhole replacement is a necessary option if the condition is beyond repair.
• Replacements are done by digging out the existing manhole and replacing it with a precast concrete structure or insert.
• Three rehabilitation options for a manhole that can be repaired: cured-in-place pipe (CIPP), spray- or hand-applied polymer linings or cementitious mortar linings.

CIPP

• For a CIPP liner, a hole that is large enough for the system to fit into must be present.
• A seal must be at the bottom of the manhole to ensure that there is no material getting between the CIPP liner and existing manhole as the joint between the two is made.
• CIPP is a sustainable option with some restrictions.

POLYMER LININGS

• Polymer linings include epoxies, polyurethanes or polyureas.
• Chemically resistant if the liner stays fully intact.
• To stay fully intact, the system must dry.
• If corrosion has developed, the original shape of the manhole will have to be formed with cementitious mortar.

CEMENTITIOUS MOTOR LININGS

• Three categories: portland cement (OPC), calcium aluminates (CAC) and geopolymers.
• These linings can be installed quickly, they require stopping infiltration and cleaning the manhole.
• They do not require the structure to be completely dry.
• Cementitious liners are easier to apply, lower in cost and have adequate chemical resistance in most situations.

These are some of the NoDig.com premium suppliers that are leading the industry with superior supplies for manhole rehabilitation and more.

Sealing Systems, Inc. – an international manufacturer and distributor of quality products for sustaining and maintaining municipal water and sewer systems by preventing inflow and infiltration. Product line includes: chimney seals, joint wraps, chemical grout, manhole adjustment rings and manhole inserts.

Sauereisen – Saueteisen specializes in the restoration of infrastructure, the prevention of corrosion, sulfur bonding compounds and the insulation of high-temperature instrumentation. Their products include, organic and inorganic corrosion-resistant materials of construction for new and rehabilitation applications.

SuperCover – SuperCover offers composite manhole frames and covers designed and inspired by challenges faced throughout various municipalities. SuperCover offers replacement manhole covers that are durable and built to last.