Harmer SML Below Ground Drainage Cast Iron Pipes and Fittings are manufactured and tested in accordance with the European Standard BS EN 877. Harmer SML Below Ground allows for direct connection from soil to drain to sewer.


SML below ground pipes are available in standard 3 metre socket-less lengths, in diameters from 100mm to 400mm, providing a high performance, lightweight, below ground cast iron soil & waste system. Pipes are produced by a state-of-the-art centrifugal casting process which produces consistent quality.


A range of fittings designed to connect multiple below ground pipes. Available in single and double branches as 45 degree and 88 degree in 100mm to 300mm diameter pipe sizes.


SML below ground couplings are specially designed for joining lengths of SML below ground pipe work and for
joints between pipes and fittings. Couplings are available in stainless steel from 100mm to 400mm and in ductile iron from 100mm to 200mm.

Bends and Offsets

A wide range of bends to accommodate change in direction, meeting a wide variety of design requirements, including single bends, long & medium radius bends and rest bends.


Designed to allow access for inspection and rodding - includes round and square access doors and access bends. To complement the range there are also other fittings such as reducers from 100mm to 300mm, plain traps and blank ends from 100mm to 300mm.

Inspection Chambers

A range of inspection chambers from 100mm to 150mm with two 45 degree branch connections. Supplied with a removable cover allowing easy access for maintenance.

  • Full system of pipes, fittings & access chambers
  • Fully compatible with Harmer SML above ground building drainage
  • CE Conformity in accordance with BS EN 877
  • Kitemark Accreditation - KM 613802
  • BBA Agreement certified no. 05/4191
  • 100% recyclable
  • Harmer SML below ground is produced from 95% recycled material
  • Robust, lightweight strong and durable
  • Excellent load bearing strength
  • Outside coating of SML below ground corresponds to BS EN 877 under BS EN ISO 13823
  • Planning and installation of SML below ground pipelines in accordance with technical regulations of:

BS EN 12056: Gravity Drainage systems inside buildings

BS EN 752: Drain & Sewer systems outside buildings

BS EN 1610: Construction and testing of drains and sewers

Approved Document H: Drainage & Waste Disposal

Sewers for Adoption: A Design & Construction Guide for Developer

  • Landscaping & Pedestrian Schemes

    Landscaping and pedestrian schemes include domestic driveways and paved areas. For these projects the aesthetics and design of the slot or channel drain is important to ensure it is discreet and fits seamlessly with the surrounding environment.

  • Distribution and Industrial Centres

    Distribution yards and industrial units typically have large surface areas to drain and must cope with heavy loads manoeuvring on a daily basis.

  • Shopping Centres & Retail Parks

    Shopping centres and retail parks need unobtrusive but effective drainage to maintain an attractive environment. Looks, style and performance are all important characteristics for these projects.

Please contact us for technical details about this product.

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