Frozen Water Pipes

This article considers how to protect water pipes from freezing, as well as what to do if they do freeze.

In terms of prevention, actions to consider are:

Material. Metal conducts heat faster than plastic, so in cold weather metal pipes cool and freeze faster than plastic ones. In some situations plastic pipes will not freeze where metal ones will (e.g. if the sub-freezing temperatures are of short duration, or only slightly below freezing, or if there is periodic water flow such as to a sink or horse drinker). In addition, flexible plastic pipes will normally not break when they freeze (although this is not true of rigid PVC). Consequently, using a flexible plastic water pipe (choose one which is rated safe for drinking water) reduces both the risk of freezing and the risk of pipe breaks.
Weld or Solder. Copper water pipes can be joined by soldering or welding. The advantage of solder is that it is easier, faster and cheaper (especially if one does it oneself). The advantage of welding is that the joints are much stronger. Although even welded joints can break, the risk is much lower than with the relatively weaker solder joints.
Shelter. Placing a pipe within a wall or on the inside of a building, rather than exposed outside, provides shelter from both the cold and wind chill. This is true even for unheated buildings. Although the pipe can still freeze if it is very cold or cold for a long time, the frequency and risk is reduced.
Burying. Placing a pipe in the ground will provide protection. If possible, it should be placed beneath the frost point, which will give complete protection from freezing. To prevent the pipe from being damaged by vehicles (e.g. cars or tractors) it needs to be buried quite deep or placed in a protective tube. The ideal case is to use a plastic pipe within a protective tube (which allows a new pipe to be run easily should the existing pipe be damaged by accident or time), covered by a warning net (which provides accidental damage from future digging) and beneath the frost line.
Insulation. The use of insulation protects the pipe from freezing, with the amount of protection dependent on the thickness and quality of insulation. Even moderate insulation will provide protection if the freezing temperatures are mild, or short-lived, or offset by periodic flow of water through the pipe.
Water Flow. A pipe with flowing water will not freeze, except in the most extreme of circumstances. During very cold weather one can protect pipes by leaving a tap slightly open to allow a constant trickle of water.
Heating Tape. This is a flat electrical cable which is attached to the pipe. An electrical current flows through the cable, heating it and thereby heating the pipe to which it is attached. See below for further discussion.
Pump and Heater. A sophisticated (although more expensive) solution is to lay two pipes, connected together so that they form a circuit (or circle) and attach a pump to move the water around the circuit. A heater is normally added to the pump, so that warm water is continually pumped around the pipe, preventing freezing. See below for further discussion.
Drain. If you do not have any means to keep the pipes from freezing, you may wish to turn off the water supply and drain the water from exposed pipes during cold weather. Although this may mean that one will have to manually provide water to the horses, at least one will not need to deal with frozen pipes.

Heating Tape

The term 'heating tape' is somewhat misleading as it is in fact an electrical cable rather than tape. The term comes from the fact that the cable is flattened (rather than being round) in order to provide greater surface contact with the pipe. It is wound around the pipe or attached to it (electrical tape works well for this purpose). The cable is designed to heat up when an electrical current is passed through it, with this heat then being passed to the attached pipe, thereby prevent the pipe from freezing.

There is normally an attached thermostat which is placed against the pipe to measure its temperature. The thermostat is used to turn the electrical current on and off, so that the pipe is only heated when it gets close to freezing. This prevents the pipe from being heated when it is warm, which would be a waste of electricity and could result in the water being overheated (see below for further discussion).

When properly installed, heating tape works well. However, there are potential considerations:

Insulation. One can over the pipe and attached heating tape with insulation. This helps keep the heat in and thereby greatly reduces the amount of electricity used to keep the pipe above freezing. However, one must not overinsulate the pipe (e.g. over 2cm of high-quality insulation) as excessive insulation can result in the cable overheating when under current and thereby being damaged. With insulated pipe, one should lay the tape straight along the pipe rather than wrapped around it, for the same reason of avoiding over-heating of the insulated cable.
Thermostat placement. If a pipe goes through different environments (e.g. part of the pipe inside and part outside), then some sections of the pipe will tend to be more exposed to the cold than others, making it difficult to regulate the pipe temperature with a single thermostat. If the thermostat is place in the relatively warm inside location then it may shut off too soon and thereby allow the colder outside section of the pipe to freeze. If it is placed on the colder outside location, it can result in the protected inside pipe overheating (we have seen one case where this was so extreme that the water to an inside horse drinker was so hot it was undrinkable and in fact almost scalding). The solution we use in these difficult circumstances is to place the thermostat in the coldest location and use thinner insulation for the warm inside pipe.
Protection from chewing. Pipes within the reach of horses should be protected; this is especially so in the case of heating tape to prevent horses receiving an electrical shock should they chew on the cable.

Pump and Heater

This is a completely successful solution, as warm water is continually pumped through the system. However, it is more expensive to install due to the additional pipe, pump and heater. There is also the cost of electricity for pump and heater. Fortunately, water pumps use only a small amount of electricity. Also, unlike the heating tape solution, one can put very thick insulation around the pipes so once the water is heated there is very little electricity required to keep it warm. Outside of the winter months, one can turn the system off so that one does not waste electricity unnecessarily on the pump.

General Notes

For pipes exposed to freezing temperatures, the most reliable solution is a heater, either heating tape or the pump-heater combination. In either case, one should insulate in order to minimize electrical heating costs.

Although these solutions will protect the pipes from freezing, drinkers hanging off the pipes may still freeze, depriving the horses of water. One may wish to use a heated water bucket or heated drinker to prevent this.

Burst Pipe

In the event of a burst pipe:

Immediately turn off the water at the mains or a stop-cock.
If the burst pipe is in an area which can be damaged by water, clean up the water and dry the area to minimize damage.
Visually inspect all the exposed pipe to see see in you have a single break or multiple breaks. If a section of pipe is bulged or deformed, it should be replaced as this section is weakened and consequently at greater risk of failing at a later date.
Repair the damage or have someone do it for you.
Turn on the water and check that the repair is successful.
Inspect the rest of the pipe for possible leaks from other breaks.
If the above takes an extended period of time, don't forget to provide water (e.g. by bucket) to the horses meanwhile.

Once all visible breaks are repaired, one needs to test for undetected breaks. Open the tap or drinker at the far end and allow water to flow. If it is just a trickle, allow it to flow until the water in the pipes fully melts (normally happens within a few minutes) and there is a normal rapid flow. Then close all taps and visually inspect the pipes for leaks. If none are visible, turn off all sources of sound (e.g. radios), put your ear to the pipe and listen for flowing water. If you hear water flowing when the taps are off (and the horses aren't drinking), then there must me an undetected leak which needs to be repaired.

If water does not flow to the far end, there may be one or more points where the pipe is still frozen. If the amount of exposed pipe is short, one can defrost these with heating tape or a hair dryer; in either case one will need to first remove insulation. If the amount of exposed pipe is too long for thawing to be practical, one can turn off the water supply and then drain as much of the pipes as possible to minimize additional damage, after which one will need to wait for warmer weather to defreeze the system. It is advised not to use a naked flame to thaw pipes, due to the risk of accidental fires.

Once the pipe is repaired, if cold weather is likely to result in subsequent frozen (and burst) pipes, one should either protect the pipes (see methods at top of page) or drain them to prevent further damage.

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