Drain insulation reduces the risk of external waste pipework freezing during cold spells, which can crack pipes and cause backing up of waste from kitchen sinks and washing machines. Typical materials include closed-cell polyethylene or rubber foam sleeves applied to exposed 32mm to 110mm waste runs on rear elevations, basement light wells and external service ducts. Insulation should comply with BS 5422 thicknesses for the relevant pipe diameter and exposure. London is at relatively low frost risk compared with other parts of the UK, but exposed pipework in side returns, basement areas and unheated outbuildings can still freeze in prolonged cold. Heat tracing tapes operating in accordance with BS EN IEC 60079 may be added where pipes are at higher risk and a power supply is available.
Drain insulation (frost protection)
Insulation of external drainage pipework to reduce the risk of freezing.
