Frozen pipes in Hull — how to prevent them and thaw safely

Every winter we get a run of calls that all sound the same. Cold snap arrives, temperature drops overnight, and by morning the kitchen tap is running fine but the bathroom is dead. Sometimes the pipe survives the freeze. Sometimes it splits and by the time it thaws you've got water pouring through a ceiling.

Hull has a particular mix that makes frozen pipes more common than the national average — lots of older housing with pipe runs in cold roof spaces, plenty of exterior walls with poorly-lagged pipes tucked against them, and a proper east-coast wind chill when it turns. This guide covers what to do to stop it happening, and what to do if it already has.

Why Hull sees more of this than most places

• Old housing stock. Terraces and 1930s semis often have long pipe runs in unheated lofts, sometimes with the cold water tank up there too. If the loft insulation is on the loft floor (which it should be), the roof space above it stays freezing.
• External walls. Many older Hull kitchens have the cold mains coming up an external wall to feed the sink. When the wind's off the Humber and the temperature drops below zero, that section is the first to go.
• Cold loft tanks. If you've still got a cold water storage tank in the loft, that's a big vulnerability. Water sitting still in a plastic tank in a freezing loft can ice over.
• Exterior taps. Garden taps that weren't turned off and drained down before winter routinely split.

How to prevent it — the boring stuff that works

1. Lag every pipe in a cold space

The single most effective thing you can do. Foam pipe insulation — the grey stuff, split down one side — costs a few pounds a metre and takes minutes to fit. Get the right diameter for your pipes (usually 15mm or 22mm) and make sure you cover:

• Every run of pipe in the loft, right up to and including the tank if you have one.
• Any pipe on an external wall, inside cupboards or behind bath panels.
• The stopcock and the pipe either side of it.
• The overflow pipe from the cistern in the loft (freezing overflows cause plenty of internal leaks).

Don't leave gaps at bends and joints — that's exactly where pipes freeze. Tape them properly. If you'd rather have someone go through the loft and do it properly with the right insulation for tanks and pipework, our pipework and tanks page lists it as a guide job from £55 (parts extra).

2. Insulate the cold water tank if you've got one

A tank jacket is a cheap job with a big payoff. And importantly — do not lag the loft floor directly under the tank. You want a bit of warmth from the house below reaching the tank base. This is a common mistake we see.

3. Drain and isolate the garden tap

Before the first frost, find the isolation valve on the pipe feeding your garden tap (usually just before it goes through the wall), turn it off, then open the outside tap to let the water drain. Leave the outside tap open through winter. Costs nothing and saves a burst.

4. Keep some heat on during cold snaps

If you're away in winter, don't turn everything off completely. Leave the heating on a low background temperature — 10 to 12 degrees is enough. It costs a bit but is much cheaper than a burst pipe. If you're going for weeks, drain the system down properly instead.

5. Open loft hatches during hard freezes

If a proper cold snap is forecast, cracking the loft hatch open for a night or two lets a little house warmth up into the roof space. Not elegant, but it works.

Signs a pipe has frozen (but not burst — yet)

• One tap runs, another doesn't. Usually the upstairs ones fail first because they're fed by the loft.
• Toilet won't refill after flushing.
• No water at all if the mains itself has frozen.
• A strange gurgling or knocking sound in the pipes.
• Frost or ice visible on an exposed section of pipe.

If you catch it before it thaws on its own, you have a chance to thaw it under control before any split lets go under pressure.

How to thaw a frozen pipe safely

1. Shut off your stopcock first. This is critical. If the frozen pipe has split, thawing it will release water fast. Turn the mains off before you do anything else. If you don't know where your stopcock is, see our shut-off guide — takes two minutes to read.
2. Open the tap the frozen pipe feeds. This gives the melting water somewhere to go and stops pressure building as the ice thaws.
3. Find the frozen section. Feel along the pipe — the frozen bit will be noticeably colder, sometimes with frost on it. Usually it's the section on an external wall or in the loft.
4. Warm it gently. A hairdryer on medium, working from the tap end back towards the frozen section. Warm cloths soaked in hot water and wrapped round the pipe. A room heater in the loft space. Slow and steady.
5. Check for leaks as it thaws. Watch the pipe and the ceiling below. As the ice melts you'll find out whether the pipe split under pressure while it was frozen.

Never do this

• No naked flame. Blowtorches, matches, candles, lighters — none of it. You'll scorch the pipe, damage nearby joists and insulation, and in a loft full of old timber and dust you're setting yourself up for a fire. This is the number one "why did they do that" story we hear.
• No boiling water poured over the pipe. Thermal shock can crack the pipe. Warm cloths, yes. Kettle straight from the boil, no.
• Don't leave it and hope. If the pipe has split, hoping it'll be fine when it thaws is how ceilings end up on the floor.

What to do if a pipe has already burst

Stopcock off, then a cold tap open to release pressure, then contain the water and ring a plumber. Photograph the source before you clean up — insurers ask. Our pipework and tanks page covers what a repair usually involves, and if the leak has soaked into floors, ceilings or walls, our drying kit hire is worth a look — a couple of days of proper drying saves months of damp problems.

The one job worth doing in autumn

If you take one thing from this: walk the loft in October with a torch and check what's lagged and what isn't. Fifteen minutes and a bag of foam sleeving from the DIY shop. It's the difference between a cold snap being a slight inconvenience and being a five-figure insurance claim.

If you'd like us to have a look — check what's lagged, insulate the tank properly, sort any exposed runs — give us a ring. Water-side only, Hull-based, and we'd genuinely rather do a lagging job in November than an emergency repair in January.