What is Manhole?

Definition of Manhole in Construction
The structure within a storm or sanitary system, that is used as a junction and access point for the below grade piping systems.

Normally the manhole is covered with a solid cast iron top called a manhole cover. In many municipalities the manhole top or cover is identified with the municipalities name and the type of manhole it covers ( storm or sanitary ).

A manhole is a very broad term, and is used in numerous circumstances. Basically the term involves access for a man into an underground system. The manhole can be constructed of precast sections, masonry, poured in place concrete, or even steel chambers can be referred to as a manhole. A manhole in many instances will have a steel or synthetic ladder cast into the sides of the manhole. With precast manholes, the concrete sections have an insert to receive the ladder for future installation. Manholes are waterproofed with a mastic ( bituminous ) product to ensure that the manhole is watertight and does not fill with water. The use of neoprene caskets between the manhole sections is also a waterproofing technique. Manholes can range from small diameters of 3 feet to extremely large assemblies that have several lines running into and out of their interiors.