Marshalls CPM produce a range of precast concrete house inspection chambers (HIC) in a variety of depths, with tongue and groove joints to BS EN 1917:2002/BS 5911-4:2002.
HIC units can be supplied banded as detailed in the tables on weights and dimensions.
The chambers, which are economic and versatile to meet the demands of domestic drainage installation, are easily handled and excavation below ground level is reduced to a minimum.
For depths in excess of 1.5m the use of a concrete surround is recommended.
Top sections
Top sections for 750mm x 600mm and larger chambers act as reducing slabs, enabling standard 600mm x 450mm covers to be fitted irrespective of the size of chambers involved.
To provide concrete top section for 1000mm x 675mm requires:
Top section for metal cover and frame 1000mm x 675mm (i.e. reducer).
Top section for concrete cover 600mm x 450mm and concrete cover slab.
Concrete cover slabs
HIC concrete cover slabs are supplied to suit the top sections, and are 695mm x 540mm overall, 60mm thick and weigh 55kgs.
Marshalls CPM house inspection chambers can be jointed quickly and easily with bituminous or butyl compounds providing a watertight seal without the use of a concrete surround. For depths in excess of 1.5m the use of a concrete surround is recommended.