Adapting and extending kitchens and bathrooms pipework
If the existing hot and cold supply is in copper, your problems are simple. Compression joints (with nuts) can be disconnected and new lengths of pipe run to the new taps using compression joints.
If the joints are capillary (soldered), heating with a blowlamp will enable them to be pulled apart and new joints made.
If the supplies are in steel pipes you’ll have to locate a threaded joint in the steel pipe-there’s one where the old taps join on but there may be others more convenient for your new pipe run farther back. Unscrew steel joints you may need to heat them first – and fit a steel-to-copper adaptor using PTFE tape for the steel side, then run new piping in copper. If the supply is in lead you will need a plumber to make a lead to copper joint from which you can pick up in copper, or to connect the lead pipes to your new taps; joining lead is a skilled job. Pipes coming down to taps over the sink will have to be extended below the kitchen sinks or bathroom basins and there turned up to meet the threaded ends of the new taps.
Pipes to the side of the new unit can run low down (where they will be hidden by the sink or basin cupboard) and up to
the new taps; pipes from below are easiest of all because they will only need cutting short to connect to the taps. Pipes on the surface of the wall are easiest to deal with but present problems if they pass from above, behind the back of the sink or basin unit to reach the taps.
Turn pipes to run parallel with the sink top, dropping down a the end of the unit to enter through end panel; or hack channel in the wall. Ideally this channel should have removable cover, but most houses survive without such refinement. Drill sink base for fitting to wall, stand it in place and mark wall for drilling and plugging.
Now fix the waste pipe; unless the old one if sound and in precisely the right position it’s quicker to scrap and fit a new waste pipe in plastic. Cut holes for waste and supply ‘ pipes in unit where necessary. With sink or basin unit away from wall fit swivel coupling; loosely to taps; complete running supply pipes to sink position.
Now tighten swivel couplings to taps using fibre washers or jointing paste and hemp for a watertight joint. Put complete unit in place, screw it to wall and connect hot and cold supplies. Turn on water and check for leaks. When you are sure everything is sound, make good and plaster and tiles.