Every winter, frozen pipes are one of the most common emergency callouts we attend across Surrey and Sussex. When water freezes inside a pipe, it expands by roughly 9%, creating enormous pressure that can split copper pipes, crack plastic fittings, and burst joints. The damage often isn't apparent until the ice thaws and water starts pouring out. The good news is that frozen pipes are almost entirely preventable with some straightforward preparation.
Which Pipes Are Most at Risk?
Not all pipes in your home face the same level of risk. The most vulnerable are those in unheated or poorly insulated spaces:
- Loft pipes — these are the number one culprit. If your loft has insulation on the floor (which keeps the heat in your rooms below), the loft space itself gets extremely cold. Any pipes running through the loft are essentially sitting in outdoor temperatures.
- Garage and outbuilding pipes — if you have a washing machine, utility sink, or outside tap supplied through a garage, those pipes are at risk.
- External wall pipes — pipes running along or inside exterior walls, especially on north-facing sides, lose heat rapidly.
- Pipes under suspended floors — ground-floor rooms with ventilated voids underneath can get surprisingly cold air flowing around the pipes.
- Outside taps and exposed external pipework — these are directly exposed to the elements.
In our service area, properties on higher ground — like those in Caterham on the Hill, Crowborough, or the Ashdown Forest villages — are particularly exposed due to their elevation and wind chill.
Insulate Your Pipes
Pipe lagging is the single most effective thing you can do. Foam pipe insulation tubes are available from any DIY shop for around £1–3 per metre, and they simply clip around the pipe. Focus on:
- All pipes in the loft, including the cold water tank (if you have one)
- Any pipes in the garage or unheated utility areas
- Pipes running along exterior walls, especially in kitchens and bathrooms
- The pipe from your outside tap back to where it enters the house
Make sure there are no gaps in the insulation, particularly at bends, joints, and where pipes pass through walls. These gaps are exactly where ice forms first.
Keep Your Home Warm Enough
During cold snaps, keep your thermostat set to at least 12–15°C, even overnight and when you're out during the day. This might seem wasteful, but the small additional heating cost is nothing compared to the damage a burst pipe can cause.
If you're going away during winter — even for a long weekend — leave your heating on a low setting. Set the thermostat to at least 12°C and ask a neighbour or friend to check on the property every couple of days. If they notice the house feels unusually cold or see any signs of a leak, they can call you or take action before serious damage occurs.
Prepare Your Outside Taps
Outside taps are the easiest pipes to freeze because they're fully exposed. Before winter arrives:
- Turn off the isolation valve that feeds your outside tap (usually found inside the house, under the kitchen sink or in a utility cupboard)
- Open the outside tap to drain any remaining water from the pipe
- Leave the tap slightly open over winter so any residual water can expand without building pressure
- If you can't isolate the tap, fit an insulated outside tap cover — these cost a few pounds from a DIY shop and provide decent protection
Fix Draughts Near Pipes
Cold draughts can freeze pipes even inside your home. Check for gaps around pipes where they pass through exterior walls — these should be sealed with expanding foam or silicone. Check for draughty air bricks near pipes under suspended floors, and consider temporarily covering them during severe cold spells (but remember to uncover them afterwards, as ventilation is important for preventing damp).
Know Your Stopcock
This isn't prevention exactly, but it's crucial preparation. Make sure everyone in your household knows where the stopcock is and can turn it off quickly. Test it every few months to ensure it still moves freely — stopcocks that haven't been turned for years can seize up, leaving you unable to shut off the water in an emergency.
What to Do If Your Pipes Freeze
If you turn on a tap and nothing comes out on a cold morning, you may have a frozen pipe. Here's what to do:
- Don't panic — a frozen pipe isn't necessarily a burst pipe. If you thaw it carefully, there may be no damage.
- Turn off the water at the stopcock as a precaution, in case the pipe has cracked and will leak once it thaws.
- Thaw gently — use a hairdryer on a low setting, hot water bottles wrapped in a towel, or warm (not boiling) water poured over a cloth wrapped around the pipe. Start from the tap end and work backwards towards the frozen section.
- Never use a blowtorch, heat gun, or naked flame — this can damage the pipe, melt plastic fittings, or start a fire.
- Check for leaks as it thaws — have towels and buckets ready. If water starts spraying, the pipe has split and you'll need to call a plumber.
Frequently Asked Questions
At what temperature do pipes freeze?
Pipes can begin to freeze when temperatures drop below -1°C, though the risk increases significantly below -6°C. Pipes in unheated spaces like lofts, garages, and exterior walls are most vulnerable. Wind chill can make exposed external pipes freeze even when the air temperature is marginally above freezing.
Should I leave my heating on when I go on holiday in winter?
Yes. Set your thermostat to at least 12–15°C while you're away. The cost of running your heating at a low level for a week is far less than the cost of repairing burst pipe damage. Also ask a neighbour or friend to check on your property every couple of days.
How do I know if my pipes are frozen?
The most obvious sign is no water coming from a tap when you turn it on, or only a trickle. You might also notice frost on visible pipes, a strange smell from drains (as ice blocks the system), or unusual sounds like banging or gurgling. If you suspect frozen pipes, do not try to thaw them with a blowtorch or direct flame — use a hairdryer or hot water bottles instead.
How much does pipe lagging cost?
Foam pipe insulation costs roughly £1–3 per metre from any DIY shop and is simple to fit yourself. For a typical three-bedroom house, you might need 10–20 metres to cover the most vulnerable pipes. Professional pipe lagging installation typically costs £100–200 for a full house — a small investment compared to the thousands that burst pipe damage can cost.