Soil/rainwater gravity drainage systems are used to convey discharges in buildings to the below ground drainage network. These systems are available in different materials and also the manner of jointing can be significantly different.

John McPeake, Wavin Ireland technical sales manager, explains considerations for selection of systems manufactured from uPVC and HDPE.

In Ireland, uPVC soil and rainwater systems are most commonly used for discharges from typical domestic appliances with intermittent wastewater up to 90°C. All uPVC Soil systems manufactured to EN1329 or EN1453 provide the options of jointing by either push fit rubber ring seal or solvent welding. It may be prudent to consider requirements for thermal expansion for either jointing system.

Tighter waste boss connections

The uPVC systems are available in colours grey, black and white and diameters 110mm and 160mm.  Also, with the increasing use of bathroom pods and the requirement to minimise the size of service shafts in buildings, engineers and installers increasingly defer to the Wavin Compact Soil system for the tighter waste boss connections.

HDPE soil systems are manufactured to EN1519 using high-density polyethylene and offers  different benefits and considerations to uPVC. HDPE Soil systems are suitable for intermittent wastewater discharges up to 100°C and continuous discharges up to 90°C.

The elasticity of HDPE allows pipes to withstand freezing of internal water and chemical resistance properties may be a more appropriate consideration for industrial applications. The Wavin HDPE soil system is available in black and a range of diameters from 56mm to 300mm.

All pipes and fittings must be joined by specialist welding to create a secure connection. There are two methods – butt-fusion welding and electrofusion welding. Both options of welding require specialist preparation and welding equipment and should only be done by trained personnel.

In butt-fusion welding, two pipe ends, or a pipe end and a fitting end are bonded by melting the circular pipe faces using a hot plate and joining them together. Such a connection can only be performed using a butt-fusion welding machine.

Electrofusion welding uses a coupler to join the pipe / fittings, an electrical current then passes through the coupler, melting the pipe/ fitting ends and connecting them to the coupler. This method requires electrofusion welding equipment.


Wavin, have designed BIM Revit families for all the Soil systems to assist in the design of above ground drainage systems. Engineers and installers are using the Wavin BIM revit packages to create an accurate model of a piping system and to detect any clashes with other services all competing for space in service shafts.

Also, the accurate schedule of quantities can reduce wastage and save a great deal of time and money on a project. Wavin BIM Revit packages along with ‘How To’ tutorials  are free to download from the Wavin website.

For more information on Wavin’s Soil Systems, or contact the Wavin Technical team