Marshalls CPM’s precast concrete box culverts are designed and manufactured in accordance with EN 14844 in both standard sizes available from stock and a bespoke range that is manufactured to customer specification, ensuring that those who require standard sizes as well as those who require something extra are catered for.

Marshalls CPM is able to offer end walls, access points, vent holes, inlets, outlets, double rungs, splayed ends, starter bars and threaded sockets, a range of different inverts, dry weather flow and dished inverts. The culverts can be supplied as standard units or vertical chambers and if being used as a channel, cover slabs can be supplied separately.  Marshalls CPM box culverts are available in square or rectangular units and can be used as single or multi-unit runs, giving excellent mechanical and hydraulic performance.

All precast concrete box culverts are manufactured to class 4 (DC4) chemical resistance in accordance with the recommendations of BRE Special Digest 1.

Marshalls CPM Box Culverts suit a wide variety of applications:
  • Highways
  • Storm and Foul Sewers
  • Sea Outfalls
  • Tunnels and Subways
  • Underpasses
  • Stream Crossings
  • Vertical Chambers
  • Open Channels
  • Shafts
  • Attenuation and Storage Tanks
Bedding, Laying and Jointing

When working in trenches, health and safety must always be observed by everyone in site at all times and Marshalls CPM recommends that box culverts should be installed on a 200 think granular bedding as specified in the Specification for Highways Works (MCDHW) or UK WIR Ltd ‘Civil engineering specification for the water industry’.

  • Priming may be applied at the works or on site
  • Position the first unit with the socket facing the direction of construction to receive the second unit
  • Fix the appropriate type of jointing tackle to the culverts and apply the Milseal rubber bitumen jointing strip to the sloping primed face of the socket to form a complete gasket mitring joints and  the corners
  • Supporting the weight of the second unit, guide it as closely as possible to the first unit taking care to exclude any bedding material
  • Carefully draw the spigot of the second culvert into the socket of the first
  • The flexible joint compound should compressed by not less than 30% to effect the necessary seal. This is achieved when the gap between the joint faces on the inside of the culvert does not exceed 10mm
  • It is recommended that the dead anchor is not relocated for jointing subsequent units until the cable or chain length is exceeded.
Click image to enlarge
Click image to enlarge
Click image to enlarge

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

For sales into Scotland please call 01698 386922 or email


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  • 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.

  • 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 Box Culverts, 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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