Conditions for Pipe Freezing Calculations

Calculations for pipe insulation to prevent freezing are based on specific assumed conditions, typically including an external air temperature of -6°C and an internal water temperature of +7°C. These calculations allow for a limited percentage of ice formation, for example, 50%, over a specified evaluation period, such as 12 hours. If practical application dictates, an insulation material with a lower thermal conductivity may be substituted if the required thickness becomes unmanageable.

Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.