Medical Sanitary Assemblies - Sinks, Basins & Taps

Guide to SHTM64

Health Facilities in Scotland

This document is intended as a guide to assist the procurement/design team in the selection and suitability of sanitary assemblies (hand washing basins, taps and sinks) within healthcare buildings (Hospitals, GP & Medical Practices).

1. Consideration of infection control, in particular legionella should be given in the installation of the sanitary assemblies
2. As legal and local regulations may change, it is worthwhile consulting the relevant authorities prior to installation
3. This advice and guidance is given without responsibilty or liability

General Considerations

  • Isolating valves should be used on each installation
  • Where possible the water pressures for the hot and cold supplies should be balanced (similar pressures)
  • Components should be sealed at the joints using suitable sanitary grade silicone sealants
  • Installations should comply with relevant water regulations to avoid the risk of contamination of the mains water supply and to ensure that back siphonage cannot take place
  • Exposed surfaces should be smooth and easy to clean

Hand Washing Basins
Hand washing is divided into either clinical or general washing.
Clinical washing is in areas where clinical procedures take place and washing of the hands and forearms should be carried out under running water.

General washing covers use by non clinical hospital staff, domestic services, patient use and the general public

Clinical Washing

  • Basins should be 'hospital pattern' non overflow designs - wall mounted with integral horizontal 'through the back' waste outlets.
  • They should ideally be a minimum width of 500mm to allow sufficient space for thorough washing.
  • The preferred material is ceramic with smooth easy to clean surfaces
  • Taps should be wall mounted with integral TMV3 level thermostatic control of the hot water and operated either by extended single lever or by sensor actuation.
  • The tap outlet should be an open outlet, horizontal spout without restrictions
  • There should be an air gap (distance between outlet and basin) of 150-200mm

Note: where it is not possible to install a horizontal outlet basin, the basin should be fitted with a flush grated (free draining, no plug waste and combined with a plastic resealing (backflow prevention) trap

The services to this equipment should ideally be concealed or ducted.

General Washing

  • 'General Pattern' basins are for non clinical hand rinsing - wall mounted ceramic basins without overflows but with a tap hole.
  • These can be smaller than clinical basins eg with a width of approx 400mm, fitted with a flush grated (free draining) waste and white plastic bottle trap.
  • Taps may be lever operated or press operation (timed flow).
  • The supply of hot water should be safeguarded with a TMV3 blending valve
  • The services to this equipment should also be concealed or ducted


  • Sink and sink tops for use in clinical procedures
  • Sinks should be made from 304 grade stainless steel without overflow and should have an integral drainer
  • The waste should be flush grated (free draining) without plug
  • Taps should ideally be wall mounted with separate lever control of the hot and cold feeds - the air gap should be 150-200mm
  • Services should ideally be concealed

Allowance is made when it is not practical to conceal the pipework. In this case a sink with tap holes may be used as follows:

  • The sink should be 304 grade stainless steel with tap holes that allow for separate pillar taps
  • Services provided should be below the sink
  • The sink may be base unit  (surface) mounted
  • The taps should be long lever pillar type taps with separate controls for the hot and cold feeds

General Care Considerations

  • Cleaning and maintenance regimes are vital both in maintaining the equipment and in combatting 'hospital acquired infections'
  • Care should be taken to use only soft cloths and non abrasive cleaners
  • Descaling cleaners should be used to remove limescale deposits from equipment
  • A regular maintenance programme should be undertaken to ensure supply fittings are working correctly in particular items such as the TMV valves and tap valves