CPM Group Ltd concrete manholes are designed, manufactured and kitemarked to BS EN 1917 and BS5911-3. The intended use is to permit access and to allow aeration of drain or sewer systems conveying sewage or surface water under gravity.

When correctly installed the manhole units are designed to withstand main road traffic loading. For further details of the specification and performance criteria please contact CPM Group Technical Department.

Please note this is a general guide and reference to drawings and specification should be made for any particular requirements.

Chamber sections should be delivered vertically on the lorry. Proprietary lifting bolts are required (available from your supplier) which fit through the 50mm diameter holes in the chamber units. Units up to and including DN1800 have 2 holes, larger diameters have 3 holes. Chains should be fitted through from the inside of the chamber unit.

Cover slabs have three lifting points requiring the use of chains with hooks

IT IS ESSENTIAL FOR THE LIFTING CHAINS OR SLINGS TO HAVE A SAFE WORKING LOAD AND SUITABLE ANGLE OF LIFT APPROPRIATE FOR THE UNIT BEING LIFTED.

Manhole bases are generally cast insitu and placing of the first chamber unit will be dependant on the particular detail required by the design.

However, it will generally be one of the following 2 types.

Cover slabs should be seated on 1 layer of sealant for manholes up to DN1200 and 2 layers for larger diameters.

Some specifications may require a 150mm concrete surround to the manhole. Proprietary shutters are available for this should it be required.

The manhole can then be completed to ground level by using either class B engineering bricks or precast concrete adjusting units with the access cover and frame finally seated at ground level.