Water Supply Industry Interpretations and Advice

  • Area of Interest : Installation
  • Topic : Insulation
  • Title : Frost protection for the supply pipe systems to, and on, allotments
  • Clause Reference : Schedule 2 paragraph 4 (b) (ii)
  • Reference Number : I15
  • Decision Date : October 2003

The requirement for frost protection for the supply pipe system to, and on allotments will be deemed to have been satisfied if the supply to vulnerable taps is isolated and the system drained providing that :-

  1. a double check-valve is fitted at ground level on each pipe serving a hose union tap, and a drain-cock fitted immediately downstream of it;
  2. the underground pipework is of a material which is more resilient to the effects of freezing (e.g. MDPE) or other means provided to prevent frost damage occurring to the underground pipework (e.g. depth of cover or insulation); 
  3. the stop valve used to isolate the supplies is not the Water Supplier’s stop cock;
  4. a single check valve is suitably located to prevent backflow of water in any temporary dead leg which would be created by isolating the supply to the taps;
  5. the pipework and taps of systems that are drained prior to the winter months shall be fully flushed when the supply to them is restored;
  6. taps shall be situated, or protected as far as possible to discourage or prevent damage from other causes including vandalism.