In a victorian terrace house, a lead water supply pipe enters the damp cellar, runs about a meter along the wall to the main brass stopcock, then converts to plastic pipe before exiting the cellar to the rest of the house (which is likely to be a mixture of copper and plastic). The stopcock is a couple of feet away from the CU. Should the supply pipe be bonded? My feeling is no, but I'd be interested in other opinions.
While I'm on the subject, a more general question. Why must any bonding be done after the main stopcock? For example where the supply tees off immediately after the stopcock, is it better to bond one of the tees, or bond just before the stopcock? Where there is a long run of supply pipe before the stopcock, is it better to bond after, with a long MPBC run back to the MET, or bond it near the MET even where that's before the stopcock?
