How to install an external cold water tap






Installing an outside tap: Installation of the external tap

The case study example is typical; the stopcock is located near to the kitchen sink to supply fresh drinking water from the mains water supply. The work area is tight but accessible. The outside wall is immediately to the right, the house has had an extension; you can see the 12 inch outside wall on the right hand side of the washing machine.


		From the outside you can see how the extension wall forms a recess. Fortunately an outside drain has been located here and is already being used for the washing machine waste. The tap will be located here thus minimizing the external pipe runs.


		It is always advisable to do as much of the plumbing work as possible prior to cutting off the water supply however the first thing to check is that you can isolate the cold mains water supply to the house, using the internal mains stopcock. This will enable you to cut and work with the cold water supply pipes. As a precaution it is always advisable to fill the kettle, as the water may be off for longer than expected. Another tip is to partly fill the bath to act as a supply for flushing the toilet with a bucket, should the need arise.


		Note the cold water supply to the kitchen sink should always be mains fed, for drinking water but the rest of the house may be mains or tank fed. If it is mains fed then the internal stopcock isolates the supply and the cold taps can be used to drain the pipework. If your system is tank fed then it may not be clear what alterations have been made to accommodate appliances i.e. they may be tank or mains fed. The diagram shows a typical tank fed system note the direct mains supply to the drinking tap in the kitchen. When working on the internal cold water supply pipes, the easiest solution to drain down, is to turn off the stopcock, and turn on the cold taps in the bathroom and the kitchen and wait for the water to stop running before starting work.


		Unfortunately in our case the stopcock was found to be seized; this would prevent the occupier turning off the cold water mains supply from inside the dwelling in the event of an emergency. Taking a closer look at the internal stopcock, you can see that the supply to the stopcock is a ½ inch plastic sheathed copper pipe. Note the earth bonding clip and wire, take care not to remove this from the pipe as it provides a vital safety earth connection. In our case, the internal stopcock will need to be replaced and the cold water mains supply will now need to be isolated from the external stopcock in the street.


		Fortunately in this case the outside street stopcock is easily accessible and clear. You may find the stopcock buried with road silt which needs to be cleared out, its always advisable to check this once in a while especially before winter sets in. The stopcock shown has a water meter attached, note the stopcock is the small tap toward the bottom right of the photo.


		Another point to note is that the stopcock may be serving more than one property; this was often the case in older housing. If so let your neighbors know, if and when, you will be turning the water off. In the case example all the houses in the street have individual outside stopcocks. Tony is using a special stopcock tool to turn the tap. You will normally be able to turn the stopcock off by hand, if it is stiff however simply cut a V notch in the end of a piece of 2 inch by 1 inch timber to act as a temporary aid.


		Now that we know how to isolate the mains water supply if need be, we can start. For the moment we have left the mains water supply on. The first task is to remove the washing machine and tumble dryer. To do this you will need to isolate the hot and cold water supplies to the machine. Note, the red and blue levers for hot and cold, the red is in the on position and the blue is off. Take care as the washing machine isolation valves may be faulty and the red and blue levers may be simply turning on their spindles and not operating the valve correctly.


		Carefully pull out the machine keeping an eye on the flexible hoses to ensure they are not stretched or damaged in any way. Once the connections are accessible at the rear of the machine slowly loosen the connections carefully one at a time. Have a cloth ready to catch any water, wriggle the hose connection but ensure that the threaded nut remains attached to the machine just in case you need to do the nut up quickly, continue until you are sure that the water supply has been isolated, If water gushes out for more than a few seconds, then you must assume that the washing machine isolation valves are faulty and you will need to turn off the mains stopcock and drain down. (explained in more detail below)


		Having removed the washing machine there is now a clear area to work in. In this case the washing machine isolation valves were working and so the mains water supply is not turned off. Therefore the first task will be to install as much of the external tap pipework as possible prior to the need to cut into the mains water pipe. Carefully measure both inside and out, to find the optimum route for the pipework. Use the existing pipes that are going through the wall as a guide. In this case we are using the washing machine outlet pipe as the guide.


		It is easier to drill through a brick joint, because mortar is softer and easier to drill than trying to drill through a solid brick, so adjust your pipe route to gain the best compromised position. If possible drill a pilot hole first to check that the exit hole is as expected The water pipe through the wall needs to be sleeved in accordance with good plumbing practice. Therefore you will need to drill an oversized hole and insert a larger diameter pipe to act as a sleeve.


		The first joint that needs to be made is the internal elbow. When using the Hep 2O pipe system, It is important to ensure that the pipe is fully inserted into the joint to make an effective seal. The distance between the two chevron marks on the pipe is equivalent to the pipe insertion depth required into the fitting. For the first joint use the special Hep 2O pipe cutters to cut the pipe on a chevron mark.


		Note the insertion depth V marks are a guide for you to know when you have fully pushed the joint home. On some occasions when you are inserting a piece of pipe between two joints you may need to cut in between the chevron marks, in which case a pencil mark needs to be measured and used to act as the guide to ensure the pipe is pushed into the full depth of the socket. A pipe support sleeve has to be inserted into the end of the pipe. You must use a pipe support sleeve on all connections made using Hep 2O pipe. Cut a length of pipe to go through the wall, allowing plenty of spare pipe for external measurement and trimming.


		Once the pipe has been cut and the pipe support sleeve inserted, push the pipe into the internal elbow joint and check that it is fully home, i.e. that the second chevron is just showing. Now give the joint a sharp tug backwards to ensure that the joint is sound. You will notice that you can rotate the joint, this is one of the benefits of the Hep 2O system, in that the O ring seal inside the joint holds it water tight whilst allowing the joint to be turned.


		Get someone to hold the internal fitting in the correct position close to the internal wall. From the outside measure the pipe so that the external socket will fit neatly against the external wall, make sure you allow for the full socket depth as previously described. Cut the pipe and insert the pipe support sleeve. To make the final connection push the fitting on firmly making sure the person on the inside holds the pipe tight to the wall.


Fitting the external bib tap You now have a pipe fitted within the wall retained by an elbow either end. One of the benefits of using Hep 2O pipework is that the next piece of pipe can be simply pushed into the elbow fitting; unlike metal systems where either a difficult soldered or compression joint is required. Fitting the bib tap is now all that is required to complete the external work. A solid brass bib tap is being used with a Hepworth push fit wall plate elbow. Position the back plate in the approximate position where you would like it located. Make sure that the location has a solid background to ensure stability and a secure fixing position.


		Now you need to measure the piece of pipe that will fit between the external Hep 2O elbow and the chosen position of the wall plate elbow, taking care to account for the insertion depth of the pipe at both ends. Cut the pipe at one end on a V mark; insert a pipe support sleeve; then push home the joint into the wall plate elbow. You will now be able to gauge the correct pipe length by positioning the wall plate elbow against the wall.


		Mark the cut off point and the insertion depth point with a pencil. Once cut insert a pipe support sleeve; then push the pipe attached to the wall plate elbow into the exposed elbow on the wall. Make sure the pipe is fully inserted up to the pencil mark then give a sharp tug backwards to ensure the joint is sound. Reposition the wall plate elbow in the position where you would like it located in this case we have positioned it centrally over the drain and this time mark the drill positions for the retaining screws. Note the ability to rotate the pipe out of the way whilst the holes are drilled.


		Drill the correct sized holes to accept the screws and use the correct sized wall plugs for the job. Use solid brass round head screws number '10' to ensure a solid fixing. It is worth getting this part right as the tap takes a lot of stress when the garden hose is connected and disconnected. Finally use plenty of PTFE tape wrapped in a clockwise direction around the thread, to bed the joint and screw the tap into the secured wall plate elbow This completes the external work so we will now return to make the internal connections.


Internal pipe connections The next step is to join the Hep 2O flexible piping system to the existing copper pipework, making sure that the external supply pipe can be independently isolated and drained from the mains supply when it is not required during the winter months.


		Therefore we will need to connect to the existing copper pipework with a Hepworth push fit Tee fitting, (not shown) which can be pushed directly on to copper. Then fit an independent stopcock (shown on the left) to isolate the external pipework from the mains and finally a double check valve (shown on the right) to prevent backflow contamination.


Backflow prevention is required because garden hoses are used for a variety of purposes including spraying weed killer, garden feeds and filling fish ponds. These situations are potentially dangerous because if the pressure was lost in the mains water supply, by a burst water main or the fire brigade practicing, the contents of your fish pond or weed killer container could be sucked back into the mains causing contamination not only to your own supply but to the whole street or town. Click her for further information on the problem of backflow.


		As before pre assemble as much as possible, Measure and cut a length of pipe that is long enough to enable you to make the final connection to the mains supply. Use the V marks on the first joint, a pipe support sleeve and push the joint home firmly.


		Use a smaller piece of pipe to make the connection between the check valve and the internal elbow, don't forget you will require a pipe support sleeve inserted at both ends. Take care to install the check valve the right way round, it has a directional arrow on the valve body which indicates the direction of the water flow. One of the benefits of the Hep 2O system is that you are now able to cable the pipe into position, through the sink unit, see photo on the left.


		Hold the top of the elbow joint firmly and push the check valve and short piece of pipe home to complete the joint as previously described. Tidy the pipe using Hepworth pipe clips which clamp the pipe into position.


		The photo on the left shows the final position of the double check valve which must be positioned inside the property to prevent freezing. And on the right the open pipe end has been cabled into the cupboard under the sink all that remains is to make the final connections.


Changing the stopcock and making the final connections For the external tap, we can see from the picture above on the right, that there is a need to Tee into the copper mains feed, then fit an independant isolating valve, and drain off facility for draining down the outside tap and associated pipework in winter as a precaution against freezing. In our case the existing brass householders stop cock under the sink, and main drain cock require replacement, these were replaced using Hep 2O components. The new fittings were pre assembled prior to turning the water off, thereby minimising disruption to the household.


		The first section to be pre-assembled is the Tee off to the outside tap shown on the right. Carefully measure the components and joints to ensure the assembly fits into the space available. Note the Tee; isolating valve, which has a flow directional arrow; and the second Tee, which has been fitted with a drain off point.


		This drain off is at the lowest part of the outside tap pipework system after the isolating valve. During the winter months it is advisable to isolate the external tap, by using the independant stop cock to drain the pipe and leave the outside tap open. The next stage is to mark the copper pipe with a pencil ready for cutting.


You would normally only be required to Tee into the cold water main above the existing householders stopcock and drain point, but in our case as these required replacement they were renewed as follows. Pre-assemble the new cold water mains stopcock and main drain off point. Make sure the stopcock is the right way round i.e. that the directional flow arrow is inline with the flow. Once assembled the final connections can be made. Turn off the cold water mains in the street, turn on the householders stopcock under the sink, and use the drain off point and the taps to drain the cold water from the pipes One benefit of the Hep 2O push fit system is that a successful joint can be made even though the pipework is wet or contains water, the fitting will make an effective seal as soon as it is pushed fully home. The second benefit is that the new polymer stopcock is not prone to seizing as there are no metal components and therefore will be easy to turn on/off for many years.


		With the water off in the street, and the pipes drained use a rounded pipe cutter called a pipe slice to cut the pipe using the pre marked point where the Tee for the outside tap will be connected. (do not use a hacksaw) When removing the existing stopcock care must be taken not to damage the pipe end to ensure an effective seal with the new fitting. Therefore the finished copper pipe end must have been cut and trimmed with a pipe slice and not a hacksaw.


		Once the old brass stopcock has been removed, clean and trim the incoming mains pipe and carefully mark the insertion depth of the new stopcock on the pipe with a pencil. (shown on the left) Push the pre-assembled stopcock and drain point onto the cold water mains pipe making sure the fitting reaches your pencil mark, then give the stopcock a sharp tug backwards to ensure an effective joint has been made.


		The (top) pre-assembly for the outside tap can now be fitted, in this example fit the Tee piece first then carefully measure the Hep 2O pipe that has been run through into the cupboard, then cut the pipe, and insert the pipe support sleeve then push home to make the connection as shown on the left. Note the earth connection point has been moved but is still at the closest point to the stopcock as possible. The final connection can now be made, the advantage of using Hep 2O is the flexibility within the pipework which allows you to bend the pipes to accept the final piece of pipe as shown on the right should there be any pipework mis-alignment.


Once the final piece has been inserted the mains water supply can be turned on, the pipe system will fill and you will need to turn the cold-water taps off. Turn on the outside tap isolating valve and check that you gain cold water from the outside tap. To protect externally installed flexible piping from ultra violet rays, it is advisable to apply a light undercoat and exterior gloss to the exposed pipework, the wall plate elbow does not require painting as it has been designed with in built protection. One final benefit of the Hep 2O system is the ability to rotate the isolating valves neatly to the side or rear of the cupboard to maximise the space available.