Replacing a bath may seem to be an ambitious do-it-yourself project but it is well within the capabilities of the determined home handyman prepared to tackle the job carefully and logically.

Here is what is involved.

As with many other plumbing projects the most difficult part is likely to be the removal of the old fitting rather than the installation of the new one.

The old bath will almost certainly be made of enamelled cast iron. The once-white enamel may be discoloured and wearing away, and may even reveal rusting bare metal underneath. Green or brown coloured stains beneath the taps indicate a long-neglected need for rewashering. The taps may look out of date and have worn chromium plating. The finish of the bath may be old and unattractive and the bath itself not panelled in.

Checking it out

First have a look at the existing bath. If there are side or end panels, strip them off and examine, with the aid of an electric torch, the water supply pipes and the waste and the overflow arrangements in the cramped and badly lit space between the foot of the bath and the wall. You will see that the water supply pipes connect the threaded tails of the taps by means of brass ‘swivel tap connectors’ or ‘cap and lining joints’.

Check whether the water supply pipes are made of copper or lead by scraping their surface with the blade of a pocket knife. If this reveals the characteristic grey sheen of lead you should think of replacing the piping. If you want to retain the lead piping see PLUMBING TECHNIQUES 3, or ask an expert – it’s not an easy task. If the pipes are of copper you should be able to tackle the entire project without professional aid.

The overflow from a modern bath is taken, by means of a flexible pipe, to the waste trap. In the past, the overflow pipe often simply led through the external wall, and was the source of incurable bathroom draughts. If your bath’s overflow is like this, you’ll have to cut it off flush with the wall.

If the bath has adjustable feet, apply some penetrating oil to the screws. Once they begin to move, lowering the level of the bath before you attempt to remove it can help to prevent damage to the wall tiling.

The alternatives

It is possible to replace your cast iron bath with a new one made of the same material, but more modern in styling. However, these baths are expensive and very heavy indeed. Carrying one into the bathroom and fitting it requires considerable strength (you’d need at least one strong helper) as well as care. There are other snags about enamelled cast iron baths. They normally have a slippery base that can make them dangerous to use – particularly by the very young and the elderly, though some are available with a non-slip surface. Furthermore, the material of which they are made rapidly conducts the heat away from the water and while this didn’t matter too much in the days when energy was plentiful and cheap, large amounts of hot water cost rather more today.

One economical alternative is an enamelled pressed steel bath. This is lighter and cheaper than enamelled cast iron but can be more easily damaged in storage or installation.

For do-it-yourself installation a plastic bath is the obvious choice. These are made of acrylic plastic sheet, sometimes reinforced with glass fibre. They are available in a number of attractive colours and, as the colour extends right through the material of which they are made, any surface scratches can be easily polished out. They are light in weight and one man can quite easily carry one upstairs for installation. The plastic of which they are made is a poor conductor of heat which means that they are both comfortable and economical to use. Many of them have a non-slip base to make them safe.

But plastic baths do have their snags. They are easily damaged by extreme heat. You should beware of using a blow torch in close proximity to one and a lighted cigarette should never be rested, even momentarily, on the rim. A fault of early plastic baths was their tendency to creak and sag when filled with hot water and, sometimes, when you got into them. This has now been overcome by the manufacturers who provide substantial frames or cradles for support; but these frames must be assembled and fixed exactly as recommended. Some come already attached to the bath.

A combined plastic waste and overflow assembly is likely to be the choice nowadays for any bath, and is obligatory with a plastic bath. If a rigid metal trap is used with a plastic bath, the material of the bath could be damaged as hot water causes unequal expansion.

You obviously won’t want to re-use the old bath taps and will probably opt for either individual modern bath pillar taps or a bath mixer. A mixer should be chosen only if the cold water supply is taken from the same cold water storage cistern that supplies the hot water system. It should not be used where the cold water supply to the bathroom comes directly from the mains supply.

How to proceed

To avoid too long a disruption of the domestic hot and cold water supplies you can fit the taps, waste and trap into the new bath before removing the old one.

Slip a flat plastic washer over the tail of each tap and insert the tails through the holes provided for them. A mixer usually has one large flat washer or gasket with two holes — one for each tap tail. Beneath the rim of the bath, slip ‘top hat’ or ‘spacer’ washers over the tails to accommodate the protruding shanks of the taps. Screw on the back-nuts and tighten them. For details, see HOME REPAIRS 7.

Bed the waste flange onto plumber’s putty or non-setting mastic, secure the back-nut and connect up the trap. Then connect up the overflow pipe.

Removing the old bath may well be the most difficult part of the procedure. Turn off the hot and cold water supplies and drain the distribution pipes from the bath taps. If you haven’t done so already, remove the bath panel to give access to the plumbing at the foot of the bath. You can try to unscrew the back-nuts holding the taps in position, but it’s generally easier to undo the nuts that connect the distribution pipes to the tails of the taps. In order to reach the one nearest the wall you may have to dismantle the overflow, either by unscrewing it or, if it is taken through the wall, by cutting it off flush with the wall. Then undo the waste connection.

The bath is now disconnected from the water supply pipes and from the branch waste pipe and can be pulled away from the wall. Unless you particularly want to save the old bath and have some strong helpers, do not attempt to remove it from the room or the house in one piece. It is very heavy. The best course of action is to break it into manageable pieces. Drape an old blanket over it to prevent flying chips of enamel and wear goggles to protect the eyes. Then, with a club hammer, break the bath up into pieces that you can easily carry away.

Place the new plastic bath in position and assemble the cradle or other support exactly as recommended by the manufacturer. It is most unlikely that the tails of the new taps will coincide with the position of the tap connectors of the old distribution pipes. If they don’t, the easiest way of making the connections is by means of bendable copper pipe. This is ‘cor-rugated’ copper tubing — easily bent by hand. It is obtainable in 15mm and 22mm sizes and either with two plain ends for connection to soldered capillary or compression joints, or with one plain end and a swivel tap connector at the other. For this particular job two lengths of 22mm corrugated copper pipe will be required, each with one end plain and one end fitted with a swivel tap connector.

Offer the corrugated pipe lengths up to the tap tails and cut back the distribution pipes to the length required for connection to the plain ends. Leave these pipes slightly too long rather than too short. The corrugated pipe can be bent to accommodate a little extra length. Now connect the plain ends to the cut distribution pipes using either soldered capillary or Type ‘A’ compression couplings.

The chances are that the distribution pipes will be %in imperial size. If you use compression fittings an adaptor— probably simply a larger olive — will be needed for connection to a 22mm coupling. If you use soldered capillary fittings, special %in to 22mm couplings must be used. Remember to keep the blowtorch flame well away from the plastic of the bath. Connect up the swivel tap connectors of the corrugated pipe and the overflow of the bath. Do this in a logical order. First connect the tap connector to the further tap. A fibre washer inside the nut of the tap connector will ensure a watertight joint. Then connect up the flexible overflow pipe of the combined waste-and-overflow fitting to the bath’s overflow outlet. Finally connect the nearer tap to the nearer tap connector.

If you have installed new pipework then you can install the entire trap, waste and water supply pipe spurs before moving the bath into position. Whatever you have decided upon, finish making all the connections, then reinstate the water supply and check for leaks.

The level of the positioned bath should now be checked using a spirit level, and adjustments made (you’ll need a spanner to adjust the adjustable feet). When all is level, fit the side and end panels in position and the job is finished.


Most baths sold today have outside dimensions of about 1675mm (66in) long, 750mm (30in) wide, and 550mm (21 in) high. Shorter baths are available for particularly small bathrooms and these are roughly 1525mm (60in) and 1375mm (54in) long. Other baths may be up to 1825mm (72in) long and 1100mm (43in) wide. They also come in different bottom mouldings to make them safe and often have handles to help the less active get in and out. Although most are basically rectangular inside and out some are oval-shaped and designed to fit into corners. There are also special baths for the disabled which are much shorter and formed in the shape of a seat.

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