Plumbing Pipe Materials Compared: Copper, PEX, Polybutylene, MDPE and Multilayer
Copper (BS EN 1057), PEX/PB (BS 7291), multilayer PEX-AL-PEX, MDPE blue (BS EN 12201), LCS, stainless press-fit; selection by application; push-fit failure modes (insertion depth, deburr); copper within 1m of boiler; MDPE buried only; PEX expansion ~50mm/10m heated; clip spacings per BS EN 806-4