- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 26 Mar 2018
A manhole, also known as an inspection chamber, provides access to underground utilities, most commonly sewer systems. This enables operatives to undertake inspections, make modifications, and carry out cleaning and maintenance.
Manholes are generally constructed where there is a change of direction and/or a change in gradient of the utilities, or where access is required for a specific maintenance purpose. They are typically positioned 0.5 m away from curb lines, preferably with the manhole cover positioned away from the wheel line of traffic.
The cover acts as a plug to protect the manhole and prevent unauthorised access. Covers can be circular, rectangular or square, and are typically made from metal or, less commonly, precast concrete, glass reinforced plastic, or a composite material.
Older manholes are usually fitted with steps on the inner side of the wall to allow easy access. Generally, if the manhole depth is less than 1 m, a step ladder is mandatory, whereas if it exceeds 2.5 m, a regular ladder must be fitted. More modern manholes may be designed so that physical entry is not required.
For more information, see Manhole chambers.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
Dos and don'ts for creating a smart home.
New ICE publication recommends pay-as-you-go tax to fund roads and other financing options.
BSRIA launches a White Paper on wearable technology and wellbeing in buildings.
Have the pressures of the market shredded the core values of professionalism?
Lead times are a measure of the amount of time that elapses between initiating and completing a construction process.
Government releases first tranche of funding for removal of unsafe high-rise cladding.
How to ensure UK transport infrastructure copes with severe winter weather.
Location shortlist for controversial new footbridge revealed.
Under the Party Wall Act a property owner has the legal right to do works that might otherwise constitute trespass or nuisance.
The rainbow JCB will be making a welcome return to the London Build Expo on 23 and 24 October at Olympia.