When the temperature drops and everything outside freezes, the last thing you need is a pipe that bursts inside your home. Still, every year during cold spells, this issue shows up again, where water gushes out from a place it shouldn’t. So, what really causes this to happen during winter months, and what can you do to stop it before things get worse? Let’s explore this below.
Why Does Cold Weather Cause Pipes to Burst?
A lot of things go on inside and around your pipes in the winter that push them closer to a burst.
Freezing Expands the Water Inside Pipes
When the temperature outside drops below the freezing point, the water inside the pipe begins to freeze, which takes up more space than liquid. The extra space presses hard against the inner walls of the pipe.
Plumbing pipes are meant to carry flowing water under pressure, not hold solid ice. As pressure rises inside the pipe, the metal or plastic wall begins to split. Once the ice melts, water pushes through the cracked section and spills into places it shouldn’t. This type of damage often goes unnoticed until water appears on a wall, ceiling, or under the floorboards. Most of the time, the process begins with a small freeze, then builds pressure quietly until the pipe bursts wide open.
Poor Insulation Leaves Pipes Exposed
If your pipe runs along a wall or through a garage or crawlspace with no insulation, it ends up exposed to cold air in winter. That cold air moves in easily and hangs around the pipe, especially in places where there’s no heating, such as basements or attics.
With nothing to trap warmth, the pipe surface cools down pretty fast. Pipes near cracked walls or drafty corners freeze much quicker than the ones installed in warmer rooms. As the air gets colder, the water inside begins to freeze. If this happens overnight or for days in a row, it starts to wear down the pipe’s weaker spots. The joints and bends take it first. They absorb the most pressure, and over time, they split open. Pipes under floors or along exterior walls face the biggest risk once the cold settles in for too long.
Temperature Swings Weaken the Pipe from the Outside
A pipe that already sits in cold air doesn’t always burst right away. The real damage starts when the temperature changes too fast. One hour, the pipe holds steady at a cold level, and the next, the outdoor temperature falls sharply below freezing. That shift shocks the material.
This isn’t about ice forming inside. It’s about how fast the pipe expands and contracts on the outside. That kind of movement bends the material in ways it can’t handle. Durable pipes, too, pipes shift at the seams when that happens too often.
You might not spot the damage right away, but that stress remains in the pipe. So the next time water pressure goes up or temperatures fall again, that spot finally gives in. Even if a pipe looks fine on the outside, it can still split days after a hard winter snap.
Closed Valves Trap Expanding Pressure Inside
Some plumbing pipes are blocked off at one end because of a shut valve. That pressure doesn’t release anywhere when the water freezes during winter. As the ice forms, it takes up more space than the liquid did. With nowhere for that pressure to go, it builds from the inside.
Pipes with closed valves on both ends are the first to burst because the expansion can’t escape in either direction. Most people don’t even realize a pipe is blocked off unless they follow where it runs. This usually happens on the taps you’ve installed outside your home and the bathrooms that you don’t use quite often.
All that trapped pressure pushes against elbows, corners, and capped ends. Those tight spots take the hit faster than a straight section of pipe, so it gives way and cracks open right where the pressure built up.
Old or Damaged Pipes
Pipes that have already worn down over time can’t handle cold weather the same way newer ones do. The metal or plastic surface starts off with small imperfections such as scratches, dents, or weak joints from old repairs. When winter hits, those spots turn into problem areas. Cold air puts uneven stress across the whole line, and the pipe gives in at its weakest point.
How to Prevent Pipe Burst in the Winter?
You can lower the chance of burst pipes during winter if you take care of a few key things early.
Insulate the Exposed Pipe Section
If you can see any plumbing pipes in your garage, basement, crawlspace, or along an outside wall, those are the ones you need to insulate before winter. You can cover each pipe with foam sleeves, fiberglass wrap, or anything meant for pipe insulation.
The one thing you need to take care of is the pipe elbows and corners first. Those spots always get cold faster than the straight sections.
You can also wrap the pipes under your kitchen or bathroom sink. It only takes a few minutes, and you don’t have to open up anything. Just cover what’s visible and easy to reach. The tighter the insulation, the more cold air it blocks. You can find pre-cut insulation at any hardware store. Slide it on by hand and close the gaps.
Keep the Heat Running in Guest Houses or Outbuildings
If you’ve got a guest house, pool house, or any separate building on your property, set the thermostat to 65 degrees during winter. You don’t have to heat the place like someone’s living in it full-time, but you can’t let it drop too low either. Pipes inside those areas will freeze just like the ones in your main house.
In case you are not planning to use the area during winter, shut off the main water supply and drain every pipe. That way, even if the temperature drops overnight, there’s no water inside the pipes to freeze. It’s the same for any part of your home that runs on a different thermostat.
Use Smart Sensors and Leak Protection Tools
So there is always a probability that your pipes may burst when you are not in your home. These days, smart temperature sensors plug into the wall and send you alerts when the room temperature is too cold. Some thermostats even have an app you can install on your phone so you can adjust the heat in the basement or guest rooms without being there.
If your power cuts off often, you can use a backup generator to run the furnace when the lights go out. You can also add water shutoff valves that stop a leak as soon as a pipe cracks. That one move saves your floors from damage while you’re away. Most of these tools don’t take long to set up and don’t require a full smart home solution.
Disconnect the Hose and Cover the Spigot
Before the arrival of the winter season, go outside and disconnect the hose attached to the spigot. If you leave one on, the water inside the spigot can freeze and crack the pipe behind it. Once the hose is off, drain it completely and store it somewhere dry. After that, cap the fixture with a foam or a faucet insulator to block cold air from hitting it directly.
Conclusion
Now you know what causes pipes to burst in winter and what steps you can take to stop it before it happens. You can disconnect hoses, add pipe covers, or set up smart sensors to cut down the risk.
If a pipe has already burst or you’re unsure what to do next, bring someone on-site fast. California Coast plumbers can visit your property, fix the damage, and walk you through every way to prevent it in the future. Don’t wait for water to ruin your walls. Call them before the temperature drops again and ruins your plumbing.