Marshalls CPM offer a range of standard heavy duty cover slabs from 900mm to 4000mm to BS EN 1917:2002 and/or BS 5911-3:2010 as well as a wide range of standard specials which are outside the British and European standard but are regularly used throughout the industry as well as a bespoke range of ‘one offs’ that require that “extra special something”.

The reinforced concrete ‘biscuits’ are used to cap a manhole chamber and provide a base for regulating brickwork or seating/adjusting rings prior to installing the manhole cover and frame.

Click image to enlarge

C = Central   E = Eccentric

  1. All slabs detailed are Type 2
  2. Weights available on request as they are dependant on the access size
  3. For details of access position, contact the technical department on 01902 356220 or
  4. DN3660 and DN4000 cover slabs are supplied in two sections
  5. All accesses have 75 x 75 corner chamfers
  6. All cover slabs are ‘heavy duty’ and are suitable for use in main roads
  7. 1050mm cover slab 750 x 750 central opening is 1400mm OD
  8. Marshalls CPM cover slabs are available in BIM (Building Information Modelling)

Special Cover Slabs

A wide range of special cover slabs can be manufactured to customer’s specifications.

Typical examples of special cover slabs supplied are:
  • Pumping stations incorporating davits and/or rebates
  • Extra heavy duty slabs for airports and ports
  • Extra large accesses
  • Slabs designed to comply with Highways Agency Specifications.
  • Multiple accesses
  • Non-circular slabs
  • Slabs with customers own reinforcement design

Marshalls CPM is able to offer a range of precast concrete standard cover slabs in BIM (Building Information Modelling) which is now a requirement for all government construction projects.

Temporary manhole covers available upon request

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.

  • 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

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To find out more about Cover Slabs, 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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