Marshalls CPM precast concrete chamber rings are manufactured with tongue and groove joints and comply to BS EN 1917:2002/BS 5911-3:2010

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The 3660mm and 4000mm chamber rings are not covered by the British Standard (therefore not kitemarked), but comply with all the relevant provisions of the European Standard. 4000mm chamber rings are supplied in two halves.

Marshalls CPM manhole chamber sections are supplied with 3 number nominal 50mm diameter holes for lifting purposes.

Crane off-load is available up to DN3000 diameter upon request, please speak to our sales team regarding off-loading on site.

Soakaway units are available in 500mm, 750mm and 1000mm depths with 75mm diameter holes, providing a minimum area of exfiltration of 50,000mm² per metre of nominal diameter per metre of depth.

Shaft/chamber sections can be supplied:
  • with or without fixed double steps or integrated ladder system
  • with holes or cut-outs
  • with bases cast-in

Marshalls CPM is able to offer precast concrete chamber rings in BIM (Building Information Modelling) which is now a requirement for all government construction projects.

For safety reasons, all chamber sections are loaded and delivered chimney fashion, when offloaded they should never be stored on their side (on the roll), but should always be laid flat.

Lorries with crane offload facilities are available for manhole units up to and including DN3000, upon request. Suitable lifting bolts for offloading and handling purposes can be purchased from Marshalls CPM and come with appropriate test certificate.

Designers and users should ensure that they have taken into account the current requirements for manhole access as detailed in the Health and Safety Code of Practice, Regulations and Guidance issued by the Health and Safety Executive under the Confined Spaces Regulations 1997 and other relevant requirements.

chamberrings table

Recommended minimum chamber diameters to suit pipe sizes.

For sales into England and Wales please call 01179 814500 or email

For sales into Scotland please call 01698 386922 or email


Click on the images below to view the image gallery.

  • Do you recommend surrounding pre-cast concrete manholes with in-situ concrete?

    Concrete surrounds to manholes are not always necessary in the majority of situations. However if the sewer is to be adopted, this may be a requirement.

  • Do you supply certificates of conformity for your standard products?

    No – they are not required as our standard products are certified under the BS ‘Kitemark’ system – certification can be viewed here.

  • What is the standard position of the access opening in cover slabs?

    The standard access position is 150mm in from the chamber wall below (measured from centre of nearest access edge to inside of chamber wall below). Other positions/access sizes/multiple access slabs can be made to order.

  • Where can I get additional assistance on the use of concrete drainage products?

    Additional assistance can be had via the Concrete Pipeline Systems Association, see

Got a question?

To find out more about Chamber Rings/Soakaways, please call our Sales Team or fill out the enquiry form and we’ll get back to you within 24 hours.

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