Frost protection for the holiday home: avoid burst pipes while the house sits empty

When the frost arrives and the holiday home stands empty, one thing above all can go wrong and get expensive: the water pipes. Water that freezes expands and can split a pipe. If nobody notices, a single burst pipe can produce damage that runs for days. Fortunately it is preventable, and it takes an hour.

Why pipes burst

Water expands when it turns to ice. If water is left in a pipe, a water heater or a trap and the temperature drops below freezing, the ice presses against the pipe wall until it cracks. It is not the frost itself that causes the damage but the pressure from ice that has nowhere to go.

The damage usually shows only when it thaws. While there is ice in the pipe, the plug holds the water back. When the temperature rises the plug melts, and then it starts running out of the crack, often inside a wall or under a floor where nobody sees it.

That is why frost damage in an empty holiday home gets large. Nobody hears it and nobody turns the water off until somebody comes by. A house that is not looked at for six weeks may have had water running for five of them.

The places that freeze first

Frost does not move evenly through a house. It finds the places with the least heat and the most cold air around them.

• Outside taps and garden hoses, which are nearly always the first casualty.
• Pipes in unheated rooms: utility room, crawl space, garage and under a raised floor.
• Pipes in external walls, particularly on the north side.
• Traps in rarely used drains, such as the bathroom floor drain and a utility room gully.
• The water heater, if it stands in a cold room and is switched off.
• The toilet cistern, which holds standing water all winter.

How to frost-proof it

If the house is not lived in over winter, the safest answer is to drain the system completely. The order is:

• Turn the water off at the mains.
• Open every tap, hot and cold, and leave them open. That releases the pressure and lets air in so the water can run out.
• Drain the water heater at its drain valve. Switch it off first if it is electric.
• Empty the toilet cistern and flush until nothing more comes.
• Pour a little antifreeze into the traps and the toilet bowl so they neither freeze nor dry out.
• Blow the pipes through with a compressor if the house has long runs that fall towards the middle.

Alternatively you can keep a constant background heat of a few degrees throughout the house. But remember that a power cut then leaves the house unprotected, and power cuts typically come during a storm, which is exactly when it is coldest.

Background heat or draining

Rule of thumb: if you can guarantee steady heat and power all winter, and somebody looks in regularly, many owners keep a low background heat and leave the water in. If the house is completely empty for long periods, or you are unsure about the power, draining is the safe answer.

There is also an argument for background heat that has nothing to do with pipes: a house kept slightly warm gets less damp and mould, because warm air carries more moisture than cold. Drain the water and leave the house completely cold and you have solved the frost problem and made the damp problem slightly worse.

The combination we see working best is to drain the water and at the same time keep a very low background heat or run a dehumidifier. Then both risks are covered, and the power use stays low because you are not trying to heat the house to room temperature.

What insurance typically covers

Most house policies cover water damage from a burst pipe, but most also carry a condition that the house must be looked after properly. In practice that means either draining the system or keeping heat on, and being able to show that you did.

We are not advisers on this, and the terms differ from insurer to insurer. But it is worth reading your own policy through once before winter, precisely because that is the only point at which you can still do something about it.

Practically, being able to document what you did helps. A couple of dated photographs of open taps and a drained water heater cost nothing and are easier to show than to explain.

If it happens anyway

If you find frost damage, the order is: turn the water off at the mains first, before you even look at the damage. Cut the power to the affected area if water has run into anything electrical. Take photographs before you clear up, because the insurer will want them. Then call the insurer and a plumber.

Do not start pulling up walls or floors before the insurer has seen it. And do not put the heating on full to dry it out quickly: that drives the moisture into the structure rather than out of it.

One hour, once a year

The whole exercise is an hour's work, done once when the season ends. It is the cheapest hour anyone spends on a holiday home, measured against what water damage costs in excess, drying time and lost letting weeks.

Put it in the calendar together with the rest of the shutdown so it does not become a separate trip. It is the same day you empty the fridge and take the bedding home anyway.

If you cannot get there yourself

If you live a long way from the holiday home, it is hard to check it when the weather turns. After a hard frost or a storm it is worth having somebody look in for the obvious things: standing water, a wrong smell, a door blown open, a missing roof tile.

We do house checks after storm and frost and send photos, so you can see for yourself instead of guessing. We are a local cleaning company based in Bork covering Bork Havn, Hemmet, Hvide Sande, Søndervig, Nymindegab, Henne Strand, Blåvand, Skjern, Tarm and Ringkøbing. If we should close the house down and look in over the winter, send us the address.