17 August 1998

For the first time, a new Euro Norm, BS EN 1401-1: 1998, stipulates regulations for minimum wall thicknesses and applications of PVC underground drainage pipes and fittings and stipulates the specific application areas where certain pipes can and cannot be used. Specifiers of underground drainage and sewerage systems need to understand the requirements of the new standard in order to continue to receive the same high standards of products and to comply with Building Regulations.

The British Plastics Federation (BPF) Pipes Group is publishing a simple guide to make the selection of the correct pipes and fittings for any application simple and straightforward.

The new standard has three classifications of pipes and fittings and outlines the applications that each type can be used for. It stipulates that Stiffness Class 4 (equivalent to British Standard BS 4660 for 110mm and 160mm pipes, and BS 5481 for 200mm, 250mm, 315mm, and 400mm) or Stiffness Class 8 pipes and fittings must be used if an installation is to comply with BS Codes of Practice and resist long-term deformation. Inferior Stiffness Class 2 pipes will need to be subjected to complex structural design load calculations and expensive and time-consuming installation techniques to achieve the same result.

For the first time, the new BS EN 1401 defines two separate application areas and the type of pipes and fittings that can be used in each:

U: application area code for areas more than one metre away from the building to which the buried pipe system is connected

D: application area code for the area underneath and within one metre from the building where pipes and fittings are underground and connected to the soil and waste discharge system.

All pipes and fittings manufactured to BS EN 1401 will be marked with these codes. Since Stiffness Class 4 or 8 pipes are suitable in both cases, they will be marked ‘UD’. The new European standard states that Stiffness Class 2 (SN2) pipes are totally unsuitable in areas where hot water discharge occurs (D applications) and strongly recommends the use of Stiffness Class 4 or 8 pipes in these applications.

The BPF Pipes Group is made up of the UK’s leading PVC pipe and fitting manufacturers and covers rainwater, soil and waste, and underground drainage products. The group was set up to promote plastic and educate the building and construction industries about the benefits of using plastic pipes. Its members offer a full technical and advisory service for specifiers, installers and stockists of plastic pipe.

For further information please complete our contact form.

Back