PTFE tape

PTFE tape is a thin polytetrafluoroethylene material used to seal threaded plumbing joints on water supply, gas and waste fittings. The tape is wrapped clockwise around the male thread before assembly, where it deforms under tightening to fill thread imperfections and create a watertight or gastight seal. UK installations comply with BS EN 751-3 for liquid and gas applications, with different grades supplied for water (white), oxygen (green) and gas (yellow). PTFE tape is widely used across London plumbing in copper compression fittings, traps and threaded brass adapters. It is identifiable by its glossy white or coloured appearance and characteristic chemical inertness. The product is not generally used on underground drainage but is regularly encountered on above ground waste and trap connections. Replacement is straightforward during routine maintenance, with full thread cleaning recommended before re-application.