A cold snap does its damage quietly. A pipe in an unheated loft freezes overnight, the ice expands, the pipe splits — and you don’t find out until it thaws and water starts coming through a ceiling. Escape of water is one of the most expensive things that can happen to a home in winter, and most of it is preventable with an afternoon’s work in autumn.
This guide splits into four parts: the checks worth doing before the first frost, how to run your home through a freeze, what to do if a pipe or boiler gives out, and what to look at once everything thaws. Most of it is straightforward DIY. We’ve flagged the few jobs where it’s worth calling a professional.
The five-minute winter checklist
Before you read any further, these are the four things that stop most winter damage:
- Know where your stopcock is and check it turns. If you can’t shut the water off, a burst pipe becomes a flood.
- Lag every pipe in an unheated space — loft, garage, outbuilding, under the floor.
- Set your heating to come on for a short burst each day, even when you’re out, and never let the house drop below 7°C.
- Drain and cover outdoor taps and disconnect hoses.
Everything below is detail on those, plus the jobs that are worth doing while you’re at it.
How long it takes, and what you’ll need
Here’s the half day broken down. You can do the tasks in any order, and none of them need more than one pair of hands — with one exception, flagged below.
Difficulty: beginner. Every task here is a DIY job. Three things are not, and we’ve said so where they come up: replacing a seized stopcock is a plumber’s job, anything involving the boiler itself needs a Gas Safe registered engineer, and roof repairs are best left to a roofer.
One person — with one caveat. Gutter clearing is the only task that puts you up a ladder. If you can, have someone foot the ladder for you, and if the roof is high, steeply pitched or you’re not confident at height, pay someone. Nothing else in this guide needs a second pair of hands.
Before the freeze
Lag your pipes — especially the ones you never see
Time: 1 hour · Beginner · 1 person
Pipes burst where the cold reaches them, which means the pipework you rarely look at is the pipework most at risk: the loft, the garage, an unheated utility, anything running against an external wall, and outside pipes to taps or oil tanks.
Check what’s already lagged. Older foam insulation goes brittle, splits and slides out of place, so it can look covered while leaving a few inches of bare copper exposed — and a few inches is enough. Pipe insulation is cheap and cuts to length with a knife; the important thing is getting the right internal diameter for your pipe and closing the gaps at bends, joints and valves.
While you’re up there, insulate the cold water tank if you have one — but insulate the sides and lid only, not the floor beneath it. Warmth rising from the house below is what keeps it from freezing.
Turn off and drain outdoor taps
Time: 10 minutes · Beginner · 1 person
Outdoor taps and the short run of pipe feeding them are the first thing to freeze. Find the isolation valve inside (usually just behind the wall the tap sits on), turn it off, then open the outside tap to let the standing water drain out. Leave it open, so any water that does get in has somewhere to expand.
Disconnect and drain hoses rather than leaving them attached, and fit an insulated tap cover if the tap is exposed.
Find your stopcock and check it actually turns
Time: 10 minutes · Beginner · 1 person
Your internal stopcock is the single most useful thing to know about your home in winter. It’s usually under the kitchen sink, sometimes in a downstairs cloakroom, utility or airing cupboard. Turn it clockwise to shut the water off.
The problem with stopcocks is that they sit untouched for years and seize solid. Test yours twice a year: close it, open a cold tap to confirm the flow stops, then reopen it. Turn it back about a quarter-turn from fully open — that small amount of play is what stops it seizing again.
If it’s stiff, don’t force it, and don’t reach for a general-purpose penetrating spray: around drinking water fittings and rubber washers, a silicone-based plumbing lubricant is the right product. If it won’t budge, or it weeps when you move it, leave it alone and get a plumber to replace it before winter rather than during it. Take two minutes to show everyone else in the house where it is, too.
Clear the gutters and look at the roof
Time: 45 minutes · Beginner · 1 person, or 2 for the ladder
Blocked gutters overflow, and in freezing weather that water refreezes against the fascia and works its way under tiles and into brickwork. Clear leaves and debris from gutters and downpipes, and check the downpipes actually run clear.
From the ground, look for slipped or cracked tiles, damaged flashing around chimneys, and any pointing that’s crumbling. Wind-driven snow finds every one of those. Cut back overhanging branches while you’re outside — a laden branch coming down in snow does far more damage than a wet one.
Know where your boiler’s condensate pipe goes
Time: 15 minutes · Beginner · 1 person
This one catches thousands of households every cold snap and almost nobody knows about it in advance.
If you have a modern condensing boiler, it drains a small amount of acidic water through a plastic pipe — and if that pipe runs outside, it can freeze. When it does, the boiler shuts itself down as a safety measure, usually showing a fault code, and you have no heating on the coldest morning of the year.
Look for a white or grey plastic pipe, roughly 20mm across, coming out of the wall near the boiler and running to a drain. If it runs a long way, or has an external bend, it’s a candidate for freezing. Lagging it with weatherproof insulation before winter is a ten-minute job. There’s a fix if it does freeze, further down this guide.
Block the draughts
Time: 45 minutes · Beginner · 1 person
Draughtproofing won’t stop a pipe freezing, but it keeps the heat you’re paying for inside and takes the edge off cold rooms.
The usual culprits of letting in a draught: letterboxes, keyholes, gaps under external doors, loose window seals, unused chimneys, gaps around skirting and floorboards, and the loft hatch itself.
Self-adhesive draught strips handle doors and windows, a brush strip or excluder handles the bottom of a door, and flexible filler deals with skirting gaps. Leave air bricks, extractor vents and any vents serving a gas appliance alone — those are there for a reason.
Bleed your radiators
Time: 20 minutes · Beginner · 1 person
Cold patches at the top of a radiator mean trapped air, which means your boiler is working harder to heat less. Bleeding them is a five-minute job with a radiator key and an old towel, done with the heating off and the radiators cold.
Our step-by-step guide walks through it: how to bleed a radiator. If you’re weighing up your heating setup more broadly, electric heaters vs gas central heating is worth a read.
Put a cold-snap kit together
Time: 20 minutes · Beginner · 1 person
Snow and ice bring power cuts, and power cuts take your heating with them if your boiler needs electricity to run. Keep somewhere accessible:
- Torches and spare batteries — better than candles, which are a fire risk in a dark house
- A first aid kit
- Bottled water and a few days of tinned or dried food that needs no cooking
- Any regular medication, plus a thermometer
- A charged power bank for phones
- Warm layers, blankets and a hot water bottle
- Your energy supplier’s emergency number, and your insurer’s
If anyone in the house depends on electrically powered medical equipment, contact your network operator about the Priority Services Register before winter.
During the freeze
Set your heating properly
If your boiler has a timer, set it so it turns on twice a day. Two short bursts a day keeps the structure and the pipework from ever getting really cold, and gets you back to a warm house.
What matters more is the floor, not the schedule — don’t let the house drop below 7°C, and if very cold weather is forecast, set your thermostat to hold that minimum even overnight and while you’re out. Heating a house from stone cold costs more than never letting it get there.
Leave internal doors open to move warm air around, and open the loft hatch during severe cold so warmth from the house reaches the tank and pipework up there. Same logic for the cupboard under the kitchen sink — open the doors and let the room’s heat at the pipes.
If you need to take the chill off a garage, outbuilding or a room the central heating doesn’t reach, electric heaters are available to hire by the day or week.
Keep paths and drives safe
Clear snow while it’s fresh — once it’s been walked on and compacted, it turns to ice and gets much harder to shift. A proper snow shovel does the job far faster than a garden spade.
Then grit. Rock salt works down to around -8°C and needs a little foot or tyre traffic to activate, so spread it thinly and evenly rather than piling it up. Grit before nightfall if a hard frost is coming, and pay particular attention to steps, thresholds and anywhere water runs off a downpipe.
Never clear ice with hot water. It refreezes into a sheet and you’ve made the problem worse.
If something goes wrong
If a pipe freezes
You’ll usually notice a tap running dry, or a trickle where there should be pressure.
- Turn off the stopcock (clockwise) to stop more water feeding the frozen section.
- Open the affected taps so there’s somewhere for water to go as the ice melts, and to relieve pressure.
- Find the frozen section — often a visibly frosted or ice-cold stretch in a loft, garage or against an outside wall.
- Remove any lagging from that section and move anything nearby you’d rather keep dry.
- Thaw it slowly, working from the tap end back towards the frozen part. A wrapped hot water bottle, warm damp towels or a hairdryer on a low setting, kept moving, all work.
- Check for splits by running a dry cloth along the pipe before you restore the supply. Ice may already have cracked it.
- Turn the stopcock back on slowly and watch the pipe for a few minutes.
Never use a blowtorch, heat gun or any naked flame on a pipe. It can burst the pipe, damage the joints and start a fire.
If a pipe bursts
- Stopcock off immediately, clockwise.
- Turn the heating off, and open every tap to drain the system down fast.
- If water is anywhere near electrics, switch off at the mains before you go near it. If you can’t reach the consumer unit safely, call an electrician or 105.
- Contain the water — towels, buckets, and move furniture and anything electrical clear.
- Photograph everything before you start clearing up. Your insurer will want evidence of the damage.
- Call your insurer and a plumber. Most home policies cover escape of water, and many include an emergency helpline.
- Dry the space out properly. Water left in plaster, floors and cavities causes mould and rot long after the visible mess has gone. Dehumidifiers and building dryers are available to hire, and for standing water in a cellar or garage, a submersible pump will shift it far faster than mopping. Our guide to using a dehumidifier covers how long to run one and where to position it.
If your boiler stops in freezing weather
Check the condensate pipe first — a fault code plus a gurgling or bubbling noise from the boiler is the classic sign it’s frozen.
- Find where the pipe is frozen, usually at a bend, an external joint or the open end.
- Pour warm — not boiling — water along the frozen section, or hold a hot water bottle or warm cloth against it. Boiling water can crack the plastic.
- Once it’s clear, reset the boiler following your manufacturer’s instructions. It should fire up normally.
- Lag the pipe before the next cold night.
If the pipe is out of easy reach, needs a ladder, or the boiler won’t restart once the pipe is clear, stop there and call a Gas Safe registered engineer.
After the thaw
Damage shows up as things warm back up, not while it’s cold, so do a lap of the property once the freeze breaks:
- Ceilings and upstairs walls for damp patches or staining
- The loft, garage and any outbuilding for drips and puddles
- Around the base of the cold water tank
- Your water meter, if you have one — spinning with everything turned off means a leak somewhere
- Outside: slipped tiles, cracked pointing, damaged gutters and downpipes, and paths lifted by frost
Photograph anything you find and report it to your insurer sooner rather than later. If you’ve had a leak, however small, run a dehumidifier in that space for several days after it looks dry.
Leaving a property empty this winter
An empty house is where the serious damage happens, because nothing gets noticed for weeks. If you’re away, or you manage a property between tenants:
- Keep the heating running on a timer or a frost-protection setting, holding a minimum of 7°C. Check whether your insurance requires it — many policies have a condition about unoccupied properties in winter, and a period beyond which cover changes.
- If nobody is going to be there for a long stretch, consider draining the system down entirely instead.
- Ask someone to check the property regularly and make sure they know where the stopcock is.
- Consider a leak or temperature sensor that alerts you remotely.
Managing multiple sites over winter? Keeping a building site working in the winter covers the commercial side.
Frequently asked questions
How long does it take to winter-proof a house?
Around four hours for a typical three-bed home.
Lagging pipework is the biggest single chunk at about an hour; clearing gutters and draughtproofing are roughly 45 minutes each; the rest are ten to twenty minute tasks.
When should I do it?
Autumn, before the first hard frost — September through November. Doing it during a cold snap is harder, colder and more expensive. The jobs that need a plumber or an engineer might be harder to fix as they might be harder to book in if other people need help too.
At what temperature do pipes freeze?
Water freezes at 0°C, but pipes in unheated spaces are at real risk once outside temperatures sit below freezing for several hours, particularly overnight.
Wind chill on an exposed pipe makes it worse. Sustained sub-zero spells are more dangerous than one cold night.
Should I leave my heating on low all the time in winter?
For an occupied, reasonably insulated home, a timed schedule is generally more efficient than constant low heat. The exception is severe cold or an empty property, where holding a minimum of around 7°C protects the pipework and is worth the cost.
How do I know where my stopcock is?
Look under the kitchen sink first, then a downstairs cloakroom, utility room, airing cupboard or under the stairs. In flats it may be in a communal cupboard. There’s also an external stop valve near your boundary, usually under a small metal cover, which is your water company’s responsibility.
Does home insurance cover burst pipes?
Most buildings and contents policies cover escape of water, but conditions vary — some require the heating to be maintained at a minimum temperature or the water drained down if a property is unoccupied for an extended period.
Check your own policy wording before winter.
Can I use boiling water to thaw a frozen pipe?
No. Thaw pipes slowly with warm water, warm towels or a hot water bottle. Sudden heat can crack the pipe, and never use a naked flame. Warm water on a frozen condensate pipe is fine — boiling water is not.
Protect your home from the freezing weather with HSS DIY
Don’t get caught out in the cold this winter.
By making sure you know follow the five minute winter checklist and your ‘before the freeze’ jobs, you can help prevent any damage to your home. Don’t worry, if something does happen, there are things you can do to stop them from getting worse.
Whether you’re lagging pipework before the first frost or drying out a room after a leak, we’ve got the kit. Pipe insulation, draught excluders, rock salt and de-icer and snow shovels are available to buy, and electric heaters, dehumidifiers and dryers and pumps can be hired for as long as you need.
Buy the materials. Hire the tools. One order. All in one place.
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