This code of practice provides guidelines and recommendations for the installation of drinking water supply systems inside buildings. It covers pipework installation, jointing methods, support systems, and the procedure for testing, commissioning, and disinfection of new installations. The standard, an adoption of BS EN 806-2, aims to ensure a safe, hygienic, and efficient water supply by preventing leakage, contamination, and inadequate pressure.
Provides guidance on the installation, testing, and commissioning of water supply systems in buildings.
Quick Reference Values
Minimum test pressure for pipework1.5 times the system design pressure
Maximum recommended flow velocity for cold water2.0 m/s
Maximum recommended flow velocity for hot water1.5 m/s
Minimum air gap for 'Type AA' unrestricted free discharge20 mm or 2 x inlet pipe diameter, whichever is greater
Maximum horizontal support spacing for 25mm (1 inch) CPVC pipe1.0 m
Minimum residual head at highest outletGenerally 0.5 bar (approx 5m), varies by fixture
Practical Notes
Pay close attention to backflow prevention methods (e.g., air gaps, check valves) at cross-connections to avoid contamination of the potable water supply.
Ensure proper pipe supports are provided as per material-specific tables to prevent sagging, especially for plastic pipes which are more susceptible to temperature effects and UV degradation.
The hydraulic pressure test must be conducted before concealing any pipework. Witnessing and documenting the test results is crucial for quality assurance.