Plastic pipes and fittings in plumbing

Plastic pipe and fittings can now be used for hot water supplies and central heating. They are easy to work with and allow the DIY plumber to tackle a wide range of jobs.

Over the last twenty years plastic has become the most popular plumbing material for above and below ground drainage, for rainwater collection and disposal, and for subsoil drainage. In the form of black polythene tubing it has also become a material widely used for water transportation on camping sites and farms. In the home, however, it has not proved popular. Although this lack of interest can partly be attributed to the conservatism of plumbers and householders, the main reason has been that up until now the plastic pipes that have been available have been suitable for cold water supplies only.

This has meant that plumbers, who have had no choice but to use copper or some other metal for the hot water or central heating system, have almost always tended to use the same material when dealing with the cold water system. Householders have doubted the ability of plastic pipework to do a good, life-long job, and have also tended to resist its use on grounds of taste: quite simply, in places where pipework is exposed to view the combination of plastic and copper (or stainless steel or iron) is not one that is very pleasing to the eye. Now, however, all this has changed. Recently the National Water Council (NWC) gave its approval to two proprietary systems of plastic plumbing, one made out of polybutylene and the other of chlorinated polyvinyl chloride (CPVC), both of which can now be used for cold and hot water supply as well as for wet central heating systems. These two rival plumbing systems should hold a special appeal for the DIY enthusiast and – now that they have gained the NWC’s approval – there is nothing to prevent them gaining widespread acceptance.

The advantages of plastic pipework

The most obvious advantage is the lightness of the pipework, which makes for ease of handling, but the most important benefit is the ease wrth which plastic can be cut and joined. This means that the level of skill you require to undertake a particular plumbing task is greatly reduced, as is the amount of time you require to carry it out. Both systems are also strong and durable, more resistant to frost than a traditional plumbing system and, unlike the latter, not subject to corrosion.

Last but not least, they are competitively priced. Plastic pipes are less vulnerable to frost because plastic is a poor conductor of heat compared to metal (which means that, unlike metal, it provides a certain amount of insulation), and because it has greater elasticity. This means that plastic pipes are not only less likely to freeze than metal ones, but also that in the event of their doing so they are much less likely to burst.

The greater degree of insulation that plastic provides also brings other benefits: it results in less heat being lost from pipe runs between radiators (or between the hot water cylinder and the hot taps),, as well as meaning that less insulation is necessary for pipework that needs to be protected against the cold. Plastic pipes aren’t subject to corrosion for the simple reason that plastic isn’t attacked by the water supply.

Electrolytic corrosion, which results in the build up of hydrogen gas and black iron oxide sludge (magnetite) and can ultimately lead to leaky radiators and early pump failure, is therefore far less of a problem when a central heating system is fitted with plastic pipes. This also means that plastic is a safer material to use for your drinking water supply pipes than metal, the use of which can, under some circumstances, present a health risk. One final point to be borne in mind before you replace metal pipes with plastic ones is that plastic is a non-conductor of electricity. This means that all-plastic plumbing systems cannot be used to earth a domestic electricity supply. You can obtain both polybutylene and CPVC tubing in the 15mm, 22mm and 28mm (1 in) diameters commonly used in domestic hot and cold water supply and in small-bore central heating.

However, in other respects – particularly as regards the flexibility of the two different types of tubing and methods of cutting and jointing – the two systems differ. So, before you undertake a plumbing task using plastic pipes and fittings, you’d do well to consider which system best suits your particular application. Polybutylene tubing Polybutylene tubing is brown in colour and naturally flexible; in this respect it differs from CPVC tubing, which is rigid. As well as being available in 3m (10ft) lengths in all three diameters, it is also obtainable as a 100m (39.0ft) coil in the 15mm (1/2in) size, and as a 50m (195ft) coil in the 22mm size.

This flexibility, and the long lengths in which the tubing is available, is particularly useful as it cuts down the time you need to spend on installation, and reduces the number of fittings necessary (which means less cost). You can thread polybutylene pipes under floors and between joists with minimal disturbance, their flexibility also allowing you to take them through apertures and round obstacles that would otherwise present serious difficulties. You can bend the tubing cold to easy bends with a minimum radius of eight times the pipe diameter; 15mm (1/2in) tube can therefore be bent to a minimum radius of 120mm and 22mm to a minimum radius of 176mm (7in). You must, however, provide a clip on either side of the bend to secure it. The flexibility ‘of polybutylene tubing means that inside of the fittings, brushing in the direction of the pipe.

It is usually necessary to apply two coats to ABS pipes and fittings. The second coat should be brushed on quickly before the first has dried. Push the pipe fully home into the fitting (some, but not all, manufacturers suggest that this should be done with a slight twisting action). Remove excess solvent cement and hold the assembled joint securely in position for about 30 seconds. If hot water will be flowing through the pipe, don’t use it for 24 hours to give time for the joint to set completely.

Joining ring-seal types

Preparation for ring-seal or push-fit jointing is similar to that for solvent welding. The pipe end must be cut absolutely squarely and all the burr removed. You should draw a line round the cut end of the pipe 10mm from its end and chamfer back to this line with a rasp or shaping tool, then clean the recess within the push-fit connector’s socket and check that the sealing ring is evenly seated. One manufacturer supplies sealing rings separately, and they should be inserted at this point.
The pipe end should now be lubricated with a small amount of petroleum jelly and pushed firmly into the socket past the joint ring.

Push it fully home and mark the insertion depth on the pipe with a pencil. Then withdraw it by 10mm (which is the allowance made for expansion). The expansion joint that is inserted into long straight lengths of solvent-welded waste pipe consists of a coupling with a solvent-weld joint at one end and a push-fit joint at the other. As with solvent-weld jointing, individual manufacturers may give varying instructions. Some, for instance, advise the use of their own silicone lubricating jelly.
Where the manufacturer supplies instructions it is best to follow these exactly.

Fittings

PVC pipe can be bent by the application of gentle heat from a blow-torch, but this technique needs practice and it is best to rely on purpose-made fittings. Sockets are used for joining straight lengths of pipe, tees for right-angled branches, and both 90° and 45° elbows are usually available. If you need to reduce the diameters from one pipe to another you can use reducing sockets These are really sockets within sockets which can be welded together, one taking the smaller diameter pipe and the other the larger. Soil outlet pipes from WCs are joined in the same way; they are merely bigger – usually 100mm (4in) – in diameter. Sockets work in the same way, but the branch junction with the main soil stack must be of a specially ‘swept’ design.

Safety and Gas, Boiler man arrested over blast

A man who inspected the boiler of the house which exploded in Oldham has been arrested, police have confirmed.
When asked if the man was a gas fitter, Mr Heywood responded: “There is speculation in the community that he was involved in some form of maintenance.

“That appears to be our understanding as well.”

Gas Safety is a Russian roulette when using bad plumbers. Always use qualified and reliable plumbers.

gas

Solvent weld jointing tools

THE TOOLS YOU’LL NEED

• hacksaw – a junior or larger – for cutting the lengths of pipe as you need them
• piece of paper – to help cut the pipe truly square
• tape measure
• file – for chamfering the pipe ends
• fine glasspaper – to abrade pipes and sockets for solvent-welding, and for cleaning up the ends of pipes where you have cut them
• pencil – for marking the cutting points and socket depths to find the working area of the pipe.

VITAL ACCESSORIES
• solvent cement – for solvent-welding
• cleaning fluid – for cleaning the pipe ends and socket fittings when making solvent-weld joints • petroleum jelly – for lubrication when inserting the pipe into the socket in push-fit joint assemblies • tissues or rag for cleaning off excess solvent or petroleum jelly.

TYPES OF PIPE Unplasticised PVC (UPVC) is used for all waste pipe applications. Modified PVC (MPVC) has rubber or some other plasticiser added to make it more resistant to shock. Chlorinated PVC (CPVC or MUPVC) is used where very hot water discharge occurs, such as washing machine out-flows. Polypropylene (PP) is an alternative to PVC and can withstand hot water – but it expands a lot and is only suitable on short runs. Acrylonitrile butadiene styrene (ABS) is stronger than UPVC and is used for waste connection mouldings.

SAFETY TIPS
• don’t smoke when you are solvent-weld jointing – solvent cement and solvent cement cleaner become poisonous when combined with cigarette smoke
• don’t inhale the fumes of solvent-weld cement or cleaning fluid – so avoid working in confined spaces • don’t get solvent-weld cement on any part of the pipe you’re not joining as this can later lead to cracking and weaknesses, especially inside sockets where the solvent cement can easily trickle down
• hold all solvent-weld joints for 15 seconds after joining and then leave them undisturbed for at least 5 minutes – if hot water is going to flow through the pipe don’t use it for 24 hours.

Joining Soil Pipes

These are joined in the same way as plastic waste pipes but are much bigger-about 100mm (4in) in diameter-so they take longer to fit. They also have some different fittings, such as a soil branch for use where the outlet pipe joins the stack, and access fittings with bolted removable plates for inspection. There are also special connectors to link to the WC pan, via a special gasket, and to link to the underground drainage system which is traditionally made of vitrified clay. The accurate moulding of the fittings and the ease of assembly means that you can confidently tackle complete replacement of a soil system.

Cut the pipe clean and square with a hacksaw or other fine-toothed saw. A useful tip to ensure a square cut is to fold a piece of newspaper over the pipe and join the edges beneath it. The paper will then act as a template. Remove all internal and external ‘burr’ or roughness at the end of the pipe, then use a file to chamfer the outside of the pipe end to about 45°.

Not all manufacturers recommend this, but it does provide an extra key for the solvent. Insert the pipe end into the fitting and mark the depth of insertion with a pencil. Using medium grade abrasive paper, or a light file, lightly roughen the end of the pipe, as far as the pencil mark, and also roughen the interior of the socket. Thoroughly clean the roughened surfaces of the socket and the pipe end using a clean rag moistened with a spirit cleaner recommended by the manufacturer of the fittings.

Select the correct solvent cement (PVC pipes need a different solvent cement from ABS ones; once again, buy all the materials needed at the same time from the same supplier). Read the label on the tin and stir only if instructed. Using a clean paintbrush apply the solvent cement to the pipe end and to the manufacturer may make both PP and either PVC or ABS systems. It is worth asking the supplier if there is an instruction leaflet supplied by the maker. There are slight variations in the methods of using each particular make of pipe and fitting.

The manufacturer’s instructions, if available, should be followed to the letter. Buying new pipe Existing waste pipe is likely to be imperial in size – 11/2in internal diameter for a sink or bath and 11Ain internal diameter for a wash basin. Metric sized plastic pipes are normally described – like thin-walled copper tubes – by their external diameter, though at least one well-known manufacturer adds to the confusion by using the internal diameter. Both internal and external diameters may vary slightly – usually by less than one millimetre between makes. This is yet another reason for sticking to one make of pipe for any single project.

The outside diameter of a plastic tube that is the equivalent of a 11Ain imperial sized metal tube is likely to be 36mm and the inside diameter 32mm. The outside diameter of the equivalent of a 11/2in pipe is likely to be 43mm and the inside diameter 39mm. If in doubt, it is usually sufficient to ask the supplier for waste pipe fittings for a basin waste or – as the case may be – a bath or sink waste. Plain-ended plastic pipe is usually supplied in 3m (10ft) lengths, though a supplier will probably cut you off a shorter piece.

Joining solvent-weld types Solvent-weld fittings are neater and less obtrusive than push-fit ones and they offer the facility of pre-fabrication before installation. However, making them does demand a little more skill and care and – unlike push-fit joints – they cannot accommodate the expansion (thermal movement) that takes place as hot wastes run through the pipe. A 4m length of PVC pipe will expand by about 13mm (just over Vfein) when its temperature is raised above 20°C (70°F). For this reason, where a straight length of waste pipe exceeds 1.8m (6ft) in length, expansion couplings must be introduced at 1.8m intervals if other joints are to be solvent welded.

This rarely occurs in domestic design, however, and use of push-fit or solvent-weld is a matter of personal preference. Although the instructions given by the different manufacturers vary slightly, the steps to making solvent-weld joints follow very similar lines. Of course, the first rule is to measure up all your pipe lengths carefully. Remember to allow for the end of the pipe overlapping the joint. When you’ve worked out pipe lengths cutting can start.

Joining plastic piping

Most waste pipes installed today are made of plastic, which is cheap, lightweight and easy to work with. A little practice and careful measuring will enable you to replace all parts of your system.

Waste systems draining baths, basins and sinks used to be made of lead, heavy galvanised steel with screwed joints, or copper. Soil pipes from WCs were traditionally cast iron, as was all the outside pipework for both waste and soil disposal. Nowadays waste and soil pipes are made of one or other of a variety of plastic materials, which may be used for repairs, extension work or complete replacement of an existing system. These plastic pipes are lightweight and easily cut, handled and joined.

They are made of materials usually known by the initials of their chemical names – UPVC (unplasticised polyvinyl chloride), MPVC (modified polyvinyl chloride), ABS (acrylonitrile butadiene styrene) and PP (polypropylene). CPVC (chlorinated polyvinyl chloride) is usually used for hot and cold water supply pipes. Pipes and fittings are available in white, grey or a copper colour, depending on type and manufacture. All these materials are satisfactory for domestic waste systems and – with one exception – can all be joined in the same way: either by push-fit (ring-seal) jointing or by solvent welding.

The exception is PP pipe. This was first developed because of its good resistance to very hot water and chemical wastes, and was therefore extensively used in industry. Nowadays, however, it is frequently used in the home for waste or rainwater drainage. The big difference between PP and other plastic pipes used in waste drainage is that it cannot be solvent-welded. All joints must be push-fit. In most situations this is no great disadvantage but it does make it important to be able to distinguish PP from other plastics. It has a slightly greasy feel and, when cut with a fine toothed saw, leaves fine strands of fibrous material round the cut edges.

Sizes of the waste pipes

When buying plastic pipe and components it is wise to stick to one brand only. Pipes and fittings from different makers, though of the same size, are not necessarily interchangeable. Most suppliers stock the systems of only one manufacturer, although the same manufacturer may make both PP and either PVC or ABS systems. It is worth asking the supplier if there is an instruction leaflet supplied by the maker. There are slight variations in the methods of using each particular make of pipe and fitting.

The manufacturer’s instructions, if available, should be followed to the letter. Buying new pipe Existing waste pipe is likely to be imperial in size – 11/2in internal diameter for a sink or bath and 11/4in internal diameter for a wash basin. Metric sized plastic pipes are normally described – like thin-walled copper tubes – by their external diameter, though at least one well-known manufacturer adds to the confusion by using the internal diameter. Both internal and external diameters may vary slightly – usually by less than one millimetre between makes. This is yet another reason for sticking to one make of pipe for any single project. The outside diameter of a plastic tube that is the equivalent of an imperial sized metal tube is likely to be 36mm and the inside diameter 32mm. The outside diameter of the equivalent of a 11/2in pipe is likely to be 43mm and the inside diameter 39mm.

If in doubt, it is usually sufficient to ask the supplier for waste pipe fittings for a basin waste or – as the case may be – a bath or sink waste. Plain-ended plastic pipe is usually supplied in 3m (10ft) lengths, though a supplier will probably cut you off a shorter piece. Joining solvent-weld types Solvent-weld fittings are neater and less obtrusive than push-fit ones and they offer the facility of pre-fabrication before installation. However, making them does demand a little more skill and care and – unlike push-fit joints – they cannot accommodate the expansion (thermal movement) that takes place as hot wastes run through the pipe.

A 4m length of PVC pipe will expand by about 13mm (just over Vfein) when its temperature is raised above 20°C (70°F). For this reason, where a straight length of waste pipe exceeds 1.8m (6ft) in length, expansion couplings must be introduced at 1.8m intervals if other joints are to be solventwelded. This rarely occurs in domestic design, however, and use of push-fit or solvent-weld is a matter of personal preference. Although the instructions given by the different manufacturers vary slightly, the steps to making solvent-weld joints follow very similar lines. Of course, the first rule is to measure up all your pipe lengths carefully. Remember to allow for the end of the pipe overlapping the joint. When you’ve worked out pipe lengths cutting can start.

WHAT JOINS TO WHAT?

Use this table as a guide to choosing new pipework – the first material mentioned is the best or most usual choice. Existing pipe copper lead iron stainless steel polythene UPVC New pipework copper, stainless steel, polythene iron, stainless steel, polythene stainless steel, copper, polythene polythene, copper, stainless steel copper, stainless steel, polythene

CONNECTING OLD TO NEW

Fitting metric to imperial pipework can be complicated by the slight differences in pipe diameters. The problem connections are: copper to copper (compression fittings)
• some metric fittings can be used directly with imperial-sized pipes (eg, 15mm fittings with 1/2in pipe and 28mm fittings with 1 in pipe)
• with other sizes you need to buy special adaptors or larger olives to replace those inside the fittings, so to connect a 15mm branch into existing 3/4in pipe you’ll need a tee 22 x 22 x 15mm with special olives for the 22mm ends of the tee. copper to copper (capillary fittings)
• metric capillary fittings with integral solder rings are not compatible with imperial pipes, but straight adaptors are available to connect the two sizes of pipe
• use these to join in short lengths of metric pipe, the other ends of which are connected to opposite ends of the metric tee
• with end-feed type fittings, extra solder can be added to make a good joint with imperial-sized pipe. copper to stainless steel – as for copper to copper connections, but usually compression fittings only. stainless steel to copper – copper to stainless steel. as above for stainless steel to stainless steel – copper to copper.

Connecting new pipes to old pipes

Improvements or additions to a domestic plumbing system inevitably involve joining new pipework into old. How you do this depends largely on whether the existing pipework is made of lead, iron or more modern materials – copper, polythene or even unplasticised PVC.

The principle of joining into existing pipework is quite straightforward. You decide where you will need your new water supply – at a bedroom basin or an outside tap. for example – and then pick a convenient point on the plumbing system to connect up your branch line’. At this point you have to cut out a small section of the old pipe and nsert a tee junction into which the branch pipe will be fitted. That’s all there is to it: laying the branch pipe will simply involve routine cutting bending and joining of new pipe, and final connection to the new tap or appliance at the other end. Before you can begin the job, however, you have to do some reconnaissance work to identify what sort of existing pipework you have.

You might be tempted to relate the plumbing to the age of the house, thinking that an old house will have an old system with lead or iron pipework. But this isn’t a reliable guide Many old properties have been modernised and so may actually have a more up-to-date system than a house built relatively recently.

Until the 1950s the only types of pipe used in domestic plumbing were lead and iron, but then these were superseded by thin walled copper piping Today there are’other alternatives too: stainless steel is sometimes used as an alternative to copper, and polythene and UPVC (unplasticised polyvinyl chloride) pipes can be installed for cold water supplies only for the type of pipe you can use. While copper is the most common one for new work, it must never be joined to galvanised iron because of the severe risk of electrolytic corrosion of the iron if the galvanising is not in perfect condition.

First things first

Before cutting into a pipe run you’ll first have to turn off the water supply to the pipe and then drain it by opening any taps or drain cocks connected to it. But this need not be too inconvenient if you make up the complete branch line before you turn the water off so you are without water only while you make the final branch connection.

Connecting into copper pipe

When taking a branch from a copper pipe it’s probably easier to use a compression tee fitting rather than a capillary fitting. A compression fitting can be made even if there is some water in the pipe run – capillary joints need the pipe to be dry – and you won’t have to worry about using a blow-torch and possibly damaging other capillary joints nearby (if they are heated up, their solder will soften and the joint will leak)

• It’s quite easy to work out how much pipe to cut out of the main run in order to insert a tee junction (of either compression or capillary fittings). Push a pencil or stick into the tee until it butts up against the pipe stop. Mark this length with your thumbs, then place the stick on top of the fitting so you can mark the outside to give a guide line. Next you have to cut the pipe at the place where the branch has to be made and prepare one of the cut ends . Now connect to the pipe the end of the tee that doesn’t have the guide line marked on the casing and rest the tee back against the pipe. You will now be able to see where the pipe stop comes to and you can then mark the pipe to give you the second cutting point.

Remove the section of pipe with a hacksaw and prepare the pipe end. With a compression fitting put on the other cap-nut and olive. If you gently push the pipe and tee sideways to the pipe run this will give you more room to position the body before you allow the pipe end to spring into place. When this is done the cap-nut can be pushed up to the fitting and can be tightened with your fingers. Both sides of the tee can then be tightened using your wrenches to give the cap-nuts about one-and-a-quarter turns. Remember that you must use a second wrench to grip the body of the fitting so it stays still as the cap-nut is tightened. If it should turn, other parts of the joint which have already been assembled will be loosened or forced out of position, and leaks will result.

The connection into the main pipe run is now complete and you can connect up the branch pipe. If you are using a capillary tee fitting there are a number of points to bear in mind. It’s easiest to use one with integral rings of solder (this saves the bother of using solder wire) and after the pipe ends and the inside rims have been prepared and smeared with flux the fitting can be ‘sprung’ into place. The branch pipe should also be inserted at this stage so all the joints can be made at the same time. When using the blow-torch, it is important to protect the surrounding area from the effects of the flame with a piece of glass fibre matting or the back of a ceramic tile. It’s also worthwhile wrapping damp cloths round any nearby capillary joints to protect them from accidental overheating and thus ‘sweating’.

Inserting a tee junction into lead pipe involves joining the run of the tee into two ‘wiped’ soldered joints. Join short lengths of new copper pipe into opposite ends of a compression tee. Measure the length of this assembly, and cut out 25mm (1 in) less of lead pipe. Join the’ assembly in with wiped soldered joints – a job that takes a lot of practice, and one you may prefer to leave to a professional plumber until you have acquired the skill. You then connect the branch pipe to the third leg of the tee.

Connecting into iron

Existing iron pipework will be at least 25 years old, and likely to be showing signs of corrosion. Extending such a system is not advisable – you would have difficulty connecting into it, and any extension would have to be in stainless steel. The best course is to replace the piping completely with new copper piping.

Connecting into polythene pipe

If you have to fit a branch into a polythene pipe it’s not a difficult job, especially if you use the same material. Polythene pipes are joined by compression fittings similar to those used for copper. Polythene hasn’t yet been metricated in the UK and each nominal pipe size has a larger outside diameter than its copper equivalent. So you’ll have to use either special gunmetal fittings for polythene pipe (still made to imperial sizes) or else an ordinary metric brass fitting a size larger than the pipe – 22mm for 1/2in polythene. You also need to slip a special metal liner inside the end of the pipe before assembling each joint to prevent the pipe from collapsing as the cap-nuts are tightened. In addition, polythene rings are used instead of metal olives in brass fittings. Apart from these points, however, inserting a tee in a length of polythene pipework follows the same sequence as inserting one into copper.

Connecting into UPVC pipe

As with polythene it’s an easy job to cut in a solvent weld tee – a simple collar fitting over the ends of the pipe and the branch. After you’ve cut the pipe run with a hacksaw you have to roughen the outsides of the cut ends and the insides of the tee sockets with abrasive paper and then clean the surfaces with a spirit cleaner and degreaser. Solvent weld cement is smeared on the pipe ends and the insides of the sockets, and the pipe ends are then ‘sprung’ into the sockets. You have to work quickly as the solvent begins the welding action as soon as the pipes meet.

Wipe surplus cement off immediately, and hold the joint securely for 15 seconds. After this you fit your branch pipe to the outlet of the tee.

Cutting and bending copper pipes

One of the advantages of domestic copper pipe is that it’s easy to cut and bend. Few tools are required and even if you’ve only a few bends to make in a pipe run, it makes sense to know how it’s done. Making accurate bends may need some practice, but it’s cheaper than buying specially-shaped fittings.

In all plumbing water has to be carried from a source to a fixture and often then to some type of exit where it can disperse as waste. Basic to all of this is that water must run smoothly with nothing causing resistance to the flow — an important factor when the pressure is low. Generally the best plumbing practice is to make pipe runs as straight and direct as possible. But sometimes bends are unavoidable (like, for example, when pipe has to go around a room or to turn down into an area below) and if available fittings are neither right for the angle nor attractive to look at, then you’ll have to bend the pipe to suit.

Copper piping, because it is both light and resistant to corrosion, is a popular choice for home plumbing work. It can be joined with either capillary or compression fittings and when bends are needed you can create the angles in several ways. The first essential is to accurately work out the pipe lengths you require. Once you’ve made the measurement double check it — it’s quite easy to forget to allow for the pipe that will fit into the socket ends of the joints. You can make the actual marks on the pipe with pencil as this is clearly visible on copper and is a good guide when you come to cutting.

Cutting pipe accurately

For smaller pipe sizes, a sharp-bladed hacksaw is the best tool to use to make the cut. You’ll need to hold the pipe firmly, but if you use a vice be careful not to over-tighten the jaws and crush the bore of the pipe. It’s important to cut the pipe square so that it butts up exactly to the pipe stop in the joint. This will ensure the pipe is seated squarely in the fitting which is essential for making a watertight seal. It will also help to make that seal. It’s surprising how near to square you can get the end just cutting by eye. But the best way to make a really accurate cut is to use a saw guide. This can be made very easily by placing a small rectangle of paper round the pipe with one long edge against the cut mark. By bringing the two short edges of the paper together and aligning them you effectively make a template that’s square to the pipe.

All you then have to do is hold the paper in place and keep the saw blade against it as you cut. Any burr that’s left on the cut edges can be removed with a file. If you intend to carry out a lot of plumbing, or are working mainly in the larger pipe sizes, it may be worthwhile buying (or hiring) a wheel tube cutter. Of course using one of these is never absolutely essential, but it does save time if you’ve more than, say, half a dozen cuts to make. And once you have one you’ll use it for even the smallest jobs. It’s quick to use and will ensure a square cut without trouble every time. You simply place the pipe in the cutter and tighten the control knob to hold it in place. The cutter is then rotated round the pipe and as it revolves it cuts cleanly into the copper. This circular action automatically removes burr from the outside of the pipe, but burr on the inside can be taken away with the reamer (a scraping edge) which is usually incorporated in the tool.

Bending copper pipe

If a lot of changes of direction are necessary in a pipe run it’s cheaper and quicker to bend the pipe rather than use fittings. This also makes the neatest finish particularly if the pipework is going to be exposed. Under a pedestal wash-basin, for example, the hot and cold supply pipes rise parallel to each other in the pedestal before bending outwards and upwards to connect to the two tap tails.

Using fittings in this situation would be more costly as well as possibly being unsightly, while the cheaper alternative, making bends, means the pipework is less conspicuous. The pipe can also be bent to the exact angle required so this method of changing direction is not limited by the angles of the fittings. And with fewer fittings in a pipe system there are fewer places where leaks can occur.

The smaller sizes of copper pipe, those most commonly used in domestic plumbing (15mm, 22mm and 28mm), can be bent quite easily by hand. The technique of annealing — heating the pipe to red heat in the vicinity of the bend to reduce its temper (strength) and so make bending easier — is unnecessary when working in these pipe sizes. But you will need to support the pipe wall, either internally or externally, as the bend is made. If you don’t you’ll flatten the profile of the pipe. Using it in this condition would reduce the flow of water at the outlet point. For small jobs a bending spring is the ideal tool, supporting the pipe internally.

It is a long hardened steel coil which you push into the pipe to the point where the bend will be made. It’s best used for bends near the end of the pipe, since the spring can be easily pulled out after the bend is made. However, it can be used further down the pipe if it is attached to a length of stout wire (which helps to push it into place, and is vital for retrieving it afterwards).

Bending techniques

You actually bend the pipe over your knee, overbending slightly and bringing back to the required angle. The spring will now be fixed tightly in the pipe and you won’t be able simply to pull it out. However, its removal is quite easy. All you have to do is to insert a bar — a screwdriver will do — through the ring at the end of the spring and twist it. This reduces the spring’s diameter and will enable you to withdraw it. It’s a good idea to grease the spring before you insert it as this will make pulling it out that much easier.

Slight wrinkles may be found on the inside of the bend, but these can be tapped out by gentle hammering. It’s wise not to attempt this before taking out the spring. If you do you’ll never be able to remove it. Bending springs are suitable for 15mm and 22mm diameter pipe. But although it is possible to bend 28mm pipe as well, it’s advisable to use a bending machine instead. This is also preferable if you have a lot of bends to make. And if you don’t want to go to the expense of buying one, you can probably hire a machine from a tool hire shop.

A bending machine consists of a semicircular former that supports the pipe externally during the bending operation and a roller that forces the pipe round the curve when the levers of the machine are brought together. The degree of bend depends on how far you move the handles.

Flexible pipe

This is a kind of corrugated copper pipe which can be bent easily by hand without any tools. You can buy it with two plain ends for connection to compression joints or with one end plain and one with a swivel tap connector for connection to a tap or ball-valve. As it’s the most expensive way of making a bend, it’s not cost effective to use it when you have to make a number of changes of direction in a pipe run. It’s not particularly attractive to look at so it is best used in places where it won’t be seen. As such it’s most commonly used for connecting the water supply pipes to the bath taps in the very confined space at the head of the bath. And it can make the job of fitting kitchen sink taps easier, particularly when the base unit has a back which restricts access to the supply pipes.

Tools for joining pipes

For cutting pipe:
• hire a wheel tube cutter (which ensures perfectly square pipe ends) or use a hack saw
• use a metal file for removing ragged burrs of metal and for squaring ends of pipe that have been cut with a hacksaw. A half-round ‘second-cut’ type is ideal.

For compression joints:
• use two adjustable spanners or pipe wrenches (one to hold the fitting, the other to tighten the cap-nut)
• steel wool to clean the surface of pipes before assembling a joint.

For capillary joints:
• a blow-torch to melt the solder
• steel-wool for cleaning pipe surfaces
• flux to ensure a good bond between the solder and copper
• solder because even if you’re using integral ring fittings (which already have solder in them) you may need a bit extra
• glass fibre mat (or a ceramic tile) to deflect the torch flame from nearby surfaces.

TIP: CUTTING PIPE SQUARELY
For a perfect fit, pipe ends must be cut square. If you’re using a hacksaw, hold a strip of paper round the pipe so its edges align and saw parallel to the paper edge. Use the same trick if you have to file an inaccurately-cut end.

TIP: PROTECT NEARBY JOINTS
With capillary fittings, the heat you apply could melt the solder in nearby fittings. To help prevent this, wrap them in wet cloths.