Fitting Plumbing Fittings

It is not difficult to put in fittings such as baths, basins and water-storage tanks. Plumbing in appliances like washing machines can also be tackled.


To avoid an unnecessarily long interruption of the domestic hot and cold water services, a new sink should be fitted with its waste and overflow, unit and with its taps before being moved into position.

If you choose a mixer rather than individual sink taps, be sure to choose a sink mixer. These have separate channels for the hot an&cold water and the two streams mix in the air after leaving the nozzle. This is because it is illegal in any plumbing ap pliance to mix water from a storage cistern and water from the rising main. In a bathroom or shower where the cold water comes from the tank it can be mixed inside the mixer.

To drain the water supply pipes prior to connecting them to the new taps you must turn off the main stop-cock and open up all hot and cold taps.

Washing machines

Plumbing-in an automatic washing machine involves providing the machine with hot and cold water supplies and making arrangements for it to be drained.

The most usual way of dealing with the water supply is to cut off the supplies to the kitchen sink, drain the supply pipes and then to tee into these pipes.

Make sure that the outlets of the tee junctions point towards the washing machine. Connect to the teepieces 15mm tubing sufficiently long to reach the washing machine’s hose connectors. To the outer end of these lengths of 15mm copper tubing fit washing machine stop-cocks. These are attractively styled valves with a compression joint inlet and an outlet designed for connection to the washing machine hoses. They are provided with a plate which can be screwed to the wall.

Where the washing machine is to be fitted in close proximity to the existing hot and cold water supply pipes it may be possible to fit special valves into these pipes (perhaps without even having to cut off the water supply) and connect the hoses directly to these valves.

The waste hose of the washing machine may be simply hooked over the edge of the sink when required. Where this is not practicable the hose can be hooked permanently into an open-ended stand-pipe fixed to the kitchen wall and discharging via a waste trap either over a yard gully or into the main soil and waste stack of a single-stack drainage system.

The stand-pipe must have its inlet at least 60cm (24in) above floor level and must have an internal diameter of at least 35mm (13/8in).


Baths are available in enamelled cast iron, pressed steel and either acrylic plastic or glass reinforced plastic. Plastic baths are recommended for DIY installation.

Plastic baths are very easily damaged by extreme heat. Never rest a lighted cigarette on the rim and be very careful when using a blow torch.

They are supplied with substantial padded metal or wooden frames or cradles. These must be assembled exactly as recommended by the manufacturer.

When replacing an old enamelled cast iron bath with a plastic one, the removal of the old bath is likely to be the most difficult part of the job. Remove the bath panel and, after cutting off the water supply and draining the pipes, disconnect the water supply pipes from the tap tails and disconnect the trap from the waste outlet. The overflow pipe may be taken through the bathroom wall to discharge in the open air. If this is the case saw through the overflow pipe flush with the wall and plug it.

If the old bath has adjustable feet, lower them before attempting to move it to reduce the risk of damaging the wall tiling or surround.

Cast iron baths are very heavy. It is best not to attempt to move it from the room intact. Drape a blanket over it and, wearing goggles, break it up with a club hammer.


Wash basins are traditionally of ceramic material but basins of enamelled pressed steel or plastic, set into counter tops, are becoming increasingly popular.

Ceramic basins may be either wall-hung or pedestal. A pedestal basin should never be supported solely by the pedestal and the plumbing fittings. Modern pedestal basins are always supplied complete with concealed brackets or hangers.

Either individual 1/2in hot and cold taps or, provided that the bathroom cold water supply is from a storage cistern and not from the main, a basin mixer may be used. In a basin mixer the two streams of hot and cold water mix in the body of the fitting. Some modern mixer sets are supplied complete with pop-up wastes.

Ceramic basins have built-in overflows. The basins used in vanity units are provided with flexible overflow tubes that connect to the waste outlet in the same way as the waste and overflow unit of a modern sink or bath.


Cold water storage cisterns used always to be made of galvanised mild steel. Particularly when connected to copper pipes this material is very subject to corrosion. Neglected corrosion will ultimately result in a leaking cistern and hundreds — perhaps thousands — of pounds worth of damage to ceilings, decorations and furnishings.

A galvanised steel cistern showing early

signs of corrosion can be saved and protected. Drain and dry the cistern. Remove every trace of rust by wire brushing (wear goggles to protect the eyes!) and with abrasives. Then apply two coats of a tasteless and odourless bituminous paint. This treatment will afford protection for several years and can be repeated when necessary.

Ultimately, though, a new cistern will be required and it is best to choose a plastic one. Plastic cisterns cannot corrode and are frost resistant. They are light, easily installed and — having rounded internal angles — are easy to keep clean.

Plastic cisterns may be of glass reinforced plastic (GRP), of polythene or of UPVC. Polythene cisterns are usually round or barrel shaped and flexible. They can therefore be flexed through small openings.

Where it is impossible to introduce a cistern of the required capacity of 227 litres (50gal) through a small trap door into the roof space, it is permissible to use two smaller cisterns, linking them together with a 28mm pipe about 2in above their bases. To avoid stagnation of the stored water the ball-valve inlet should be connected to one of the cisterns and the distribution pipes taken from the other.


No bathroom nowadays is complete without a shower. Showers save both time and money. It is possible to have four or five showers in the time — and with the same amount of hot water — as one sit-down bath.

A shower may be fitted over a bath or installed in its own separate shower cubicle. An independent shower in a cubicle can be provided wherever there is a floor space of lm by m in plan — on a landing, in the corner of a bedroom or even in the cupboard under the stairs.

Where a shower is to be supplied with hot water from a cylinder storage hot water system there are certain design requirements that are essential to success. The hot and cold supplies to the shower must be under equal pressure. This means that they must both come from the cold water storage cistern. The cold supply must not come direct from the main

The storage cistern must be sufficiently high above the shower sprinkler to give an adequate spray. Best results will be obtained if the base of the cold water storage cistern is about 1.5 metres above the shower sprinkler but the absolute minimum hydraulic head for a satisfactory

shower is 1 metre. As a safety precaution it is best if the cold supply to the shower is taken as a separate pipe from the cold water storage cistern and not as a branch from another cold water distribution pipe.

Where the cold water storage cistern is too low to give an adequate shower the best solution is usually to construct a substantial wooden platform in the roof space and to raise the cistern on to it, lengthening the connecting pipes by inserting new lengths of copper tube linked with compression joints. Where this isn’t possible an electric booster pump may be installed to give adequate pressure.

Where these design requirements cannot be met, another alternative is to install an instantaneous electric shower. These need only to be connected to the rising main by means of a 15mm branch pipe and provided with a suitable supply of electricity. Water from the main is heated by powerful electric elements as it passes through the appliance. Increasing the flow of water lowers the temperature while reducing the flow raises the temperature. Modern instantaneous electric showers usually have an anti-scald cut-out device for safety.

All showers other than instantaneous electric ones require some kind of mixing valve to mix the streams of hot and cold water to the required temperature. The bath taps provide the simplest mixing valve. With both the basic push-on shower attachments and with the more sophisticated bath/shower mixers, the hot and cold taps are adjusted until the required temperature is achieved.

Manual mixing valves mix the hot and cold water in one fitting, control of temperature and — in some cases — flow, are obtained by turning a large knurled control knob.

More sophisticated still are thermostatic mixing valves. These are able to accommodate minor differences in pressure between the hot and cold water supplies. They eliminate the risk of scalding if pressure on the cold side of the shower falls because, for instance, someone has flushed a lavatory or drawn off cold water from a basin tap. Where a thermostatic mixing valve is fitted there is no need to take a separate cold supply pipe to the shower from the cold water storage cistern. It can be taken as a branch from a pipe supplying other bathroom appliances but it must originate from the storage cistern, not from the main.

It is impossible to obtain a satisfactory shower using an instant electric type which features separate on/off and temperature controls. This type of shower heats the water as it passes through the heater and it is this feature which limits the amount of water available, as this will also vary with the season. In winter the mains water temperature is lower, so you will obtain even less hot water.

The best shower of all is the thermostatically controlled mixer type, which automatically compensates for normal pressure changes to the incoming water.

Waste disposal units

Sink waste disposal units are plumbed permanently into the outlet of the kitchen sink to dispose of soft kitchen wastes such as vegetable peelings, food scraps, dead flowers, apple cores and so on. A capacitor-start 420 watt (1/2hp) induction motor operates powerful steel blades to grind these wastes into a slurry that is then flushed into the drainage system by turning on the cold tap.

Where a standard waste disposal unit is to be fitted the sink must have an 89mm (31/2in) outlet instead of the usual 38mm (11/2in) outlet, although at least one unit is made with the option of a 38mm (11/2in) outlet and a correspondingly lower handling capacity. Both enamelled steel and stainless steel sinks are available with outlets of this size. The outlets of existing stainless steel (but not enamelled steel) sinks can be enlarged to the size required with a special cutter usually available on hire from the manufacturer of the disposal unit.

The electrical power supply to the unit must be taken from a 13 amp outlet. A fused plug and socket connection is acceptable but a switched fused connection unit is preferable.