If temperatures drop, the risk of water pipes breaking increases. If water then leaks uncontrollably, it can cause serious damage. Then it is called to act quickly. But it is best to treat the pipes right away so that the frost damage cannot occur in the first place.
The reason why water pipes can break in winter is simple physics: when water freezes in the pipes, it expands. "Ice has a larger volume than liquid water – you can easily observe this yourself with ice cubes in the refrigerator – and pushes the pipes apart," explains Andreas Braun, who is a consultant for the plumbing sector at the German Sanitation, Heating and Air Conditioning Association (ZVSHK). "Since water is incompressible, the pipes cannot withstand the pressure and the joints are forced apart or the pipes break or. burst."
Not every break leads to flooding
However, a broken pipe does not yet necessarily lead immediately to flooding. "If you’re lucky, the entire pipe is evenly frozen for now and no water leaks from the broken spot at first," Braun says. If you notice this – for example, because no more water comes out of the tap or heating is no longer warm – and then quickly turn off the water, you can still prevent a major water damage.
"But if you’re unlucky – and unfortunately that’s what happens in most cases of a burst pipe – the burst initially goes undetected. Then either water flowing in can push the ice plug away or it thaws and then the water runs out of the pipe uncontrollably."If the pipe breaks unnoticed outside, entire driveways, schoolyards or gardens are flooded. If this happens in the building, the water can also run into the masonry.
Turn off the water pipe near the point of damage
Pipes that do not have regular flow, are located outdoors, or run through unheated rooms with open windows have the greatest risk of breakage. "In and of itself, it takes a while for a pipe to freeze," Braun says. "But at about minus five degrees, this can also happen quite quickly within a few hours if the pipe is not insulated, for example on the terrace."
If the pipe has then burst and the water has leaked out, the expert advises first and foremost to turn off the water pipe if possible close to the point of damage. "If that doesn’t happen, the main tap has to be turned off first."
In the outside area should be gritted if necessary, so that no black ice develops. If the water runs into the apartment, the fuse should be taken out, the furniture put up and the water skimmed off. Rooms then need to be dried – with condensation dryers if necessary. The damage should be reported to the insurance company immediately – here building and household insurance take effect.
Pipes need to be repaired by a professional
With the repair of the lines Braun advises urgently to a specialist. "For a layman, a broken pipe is almost impossible to repair and the extent of the actual damage is very difficult to estimate.
According to the Ordinance on General Conditions for the Supply of Water, work on drinking water pipes may only be carried out by Registered Installation Companies – so-called contract installation companies. In case of doubt, a leak test is also recommended, so a plumber should definitely get to it," says the expert. Braun has a number of tips to prevent this from happening in the first place. The first one already starts during the construction of the house: Drinking water pipes have to be laid frost-free, for example at a depth of one meter – depending on the region and how often it gets really cold there. "But that should be taken into account in buildings anyway, and usually every plumber knows well about that," says Braun.
If the pipes do have to be laid in the frost-prone area, the expert advises insulation and pipe trace heating. The latter is an electric heating tape applied to the pipe. If the temperature falls below a certain level, the band reacts, warms the line and automatically switches off again. "But it’s also imperative that this be installed by a professional in order to avoid possible damage.", says Braun.
Light drip from the pipe prevents frost
Also the inhabitants should consider in the winter a few small things preventively, before the frost comes. "The easiest option would be to let a little water keep running. So to leave the faucet always very slightly open, that sufficient water runs out and fresh water always comes again," says Braun. "As long as water is flowing, it does not freeze."
Similarly, heaters in cold rooms should never be turned off completely, but should be turned up very slightly. Thermostatic valves have an anti-freeze setting for this purpose – if you set the thermostat knob to the snowflake symbol, the radiator will go into operation if the temperature is too low. Pipes to outdoor taps that are not frost-proof should be completely emptied and then blocked off. "In practice, the use of frost-proof outdoor faucets that drain themselves has proven successful," says Braun. "Thus at least from this side in the winter no danger for a pipe break threatens."