Concrete Drainage

Across the world the construction of drainage systems using pre-cast elements is being replaced by insitu slipform construction.

The reasons are quite simple and unambiguous: -

  • Wholly mechanised process free from manual handling
  • Reduced cost
  • High productivity
  • Rigorous process quality control
  • Improved product durability
  • Flexibility with minimal radii achieved
  • Reduced environmental impact


Extrudakerb can provide a wealth of experience for the design and construction of insitu slipform drainage systems having placed over 1 million cubic metres of concrete over the past 30 years.

Extrudakerb are able to advise Clients how to best make use of the many advantages of the slipform process and accelerate programme whilst reducing costs.

Extrudakerb offer a range of insitu concrete linear drainage systems; including open water channels, combined surface water channel / carrier drains, slot drain and kerbs. Being an equipment manufacturer as well as a contractor we can offer bespoke moulds and paver set up configurations to suit any application.

Insitu concrete linear drainage systems are typically constructed prior to adjacent carriageway surfacing on top of a sub base foundation with the depth of the insitu product being equal to the depth of adjacent pavement. Insitu concrete linear drainage details can though be constructed against fully or partially constructed pavement.

Typically a 28/35N concrete is proposed although higher strength mixes are available if required.

Download Brochure

Surface Water Channel

A well trusted system with many profile variations.

Bespoke profiles can be paved fully free standing or directly against existing carriageway which is at various stages of construction.

Extrudakerb can design, develop, and build moulds to suit your site presentation and requirements.

Outfalls are constructed using bespoke timber formwork and precast concrete rising sections (adjusting units).

Where applicable Extrudakerb can develop outfall layouts including grating types, again to suit site presentation and requirements.

Typically, a 28/35N air entrained concrete is proposed although higher strength mixes are available if required.

Slot Drain

Slot drains provide a relatively large capacity carrier drain integral within a section of minimal footprint with surface drainage water accessing the carrier drain through a continuous vertical slot.

Many diameters and profiles are available both with and without a kerb up stand.

Profiles can be paved fully free standing or directly against existing carriageway which can be at various stages of construction.

The bore is formed either by paving over an inflated void former that is removed once concrete set is achieved or by means of a telescopic steel tube that is part of the slipform mould, a temporary compressible spacer is inserted into the slot during paving and removed, once concrete set is achieved thus ensuring a uniform slot profile.

Removal of the inflated void former and / or the compressible spacer enables a full CCTV survey of the bore to immediately confirm quality and integrity.

All slot drain profiles are load tested and certified to provide a D400 loading capability.

Extrudakerb offer an in house D400 load testing facility in line with their ISO 9001 accreditation.

Outfalls (LDO’s) can include silt traps and are constructed using modular sacrificial polypropylene formwork and connectors, as well as precast concrete rising sections, where required, so that integrity of the drain is maintained.

Access points or rodding points (LDA’s) are constructed using modular sacrificial polypropylene formwork and connectors.

Typically, a 28/35N air entrained concrete with polypropylene fibres is proposed although higher strength mixes are available if required.

envelopephone-handset linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram