Tennessee winters are mild enough that a lot of houses here were built without the pipe protection that is standard further north. Crawlspaces are vented. Hose bibs are not always frost-proof. Supply lines run through unconditioned space.
Then the temperature drops into the teens for three days and the phone does not stop ringing. Almost all of it is preventable, and most of the prevention costs very little.
The thing most people get backwards
Pipes usually do not burst while they are frozen. Water expands as it freezes, and the pressure builds between the ice plug and a closed faucet downstream. The pipe fails at its weakest point — and very often that failure only reveals itself when the ice melts and water starts moving again.
Before the cold arrives
Disconnect every garden hose
This is the single highest-value item on the list and it takes two minutes. A hose left attached traps water in the bib and in the pipe behind it, and that section is on an exterior wall where it will freeze first. A very large share of the burst-pipe calls we take in a cold snap trace back to a connected hose.
Insulate exposed pipe
Foam pipe sleeves cost very little and take an afternoon. Priority order: pipes in a vented crawlspace, pipes in an unheated garage or attic, and any run along an exterior wall on the north side of the house.
Close crawlspace vents
Vented crawlspaces are there for moisture control in summer. In a hard freeze they channel cold air directly across your supply lines. Close or block the vents when a serious cold snap is forecast, and remember to reopen them in spring.
Know where your main shutoff is
Find it before you need it, and make sure it actually turns. A seized main valve discovered during an emergency is a bad afternoon. If yours will not move, that is a cheap thing to replace on a normal day.
Seal the obvious air leaks
Gaps around where pipes enter the house, an open crawlspace door, a missing dryer vent flap. Cold air finding its way to a pipe is what causes the freeze, and expanding foam is inexpensive.
When a hard freeze is forecast
- 1Let a faucet on an exterior wall drip — a slow, steady drip, not a trickle. Moving water is much harder to freeze, and an open tap relieves the pressure that actually bursts pipes.
- 2Open the cabinet doors under sinks on exterior walls so household heat reaches the plumbing.
- 3Keep the thermostat at a consistent temperature day and night. Setting it back overnight during a freeze saves very little and risks a great deal.
- 4If you are leaving town, do not turn the heat off. Set it no lower than about 55°F, and consider shutting off the water at the main and draining the system.
- 5Open the garage door as little as possible if there is plumbing in there.
If a pipe is already frozen
Open the affected faucet first. That gives melting water somewhere to go and relieves pressure as the ice releases.
Then apply gentle heat to the frozen section if you can reach it — a hair dryer, a heat lamp, or towels soaked in hot water. Work from the faucet end back toward the frozen area so melt water can escape.
Never use an open flame, a propane torch, or a kerosene heater on a pipe. It is a fire risk, and on plastic pipe it will destroy the line.
And know where the main shutoff is while you do this, because if the pipe has already split you will find out the moment the ice clears.
If a pipe has burst
- 1Shut the main valve immediately — clockwise until it stops, or a quarter turn if it is a lever.
- 2If water is near outlets, panels, or a furnace, cut power to that circuit before entering the area.
- 3Open the lowest faucets in the house to drain the system and reduce what is still in the pipes.
- 4Move rugs, lift furniture, and get boxes off the floor. The first ten minutes decide how much flooring survives.
- 5Call. Details on our emergency plumbing page.
Which pipe material handles freezing best
PEX tolerates freezing considerably better than rigid pipe because it can expand slightly rather than splitting. It is not freeze-proof, but it survives events that would burst copper.
Copper and CPVC both split. Old galvanized is the worst of all, because it is already narrowed by corrosion and it fails at threaded joints.
If you are already considering a repipe for other reasons, freeze resistance is a real point in PEX's favor here.
A note for rural and seasonal properties
Well houses and pump houses need heat or good insulation, and a frozen pressure tank or switch will leave you without water even if the house plumbing is fine. Frost-free hydrants in pastures only work if they were installed deep enough and the drain hole is not blocked.
For lake cottages and seasonal homes around Harrison and Soddy-Daisy, proper winterization — draining the system and adding antifreeze to traps — beats leaving heat on all winter.
If you want a pre-winter check on the crawlspace, hose bibs, and shutoffs, we do that across Ooltewah and the surrounding communities. The estimate is free.
Frequently asked
Yes, on fixtures served by pipes on exterior walls or in unheated space. A slow, steady drip keeps water moving and, more importantly, relieves the pressure that actually bursts pipes. The water cost of a couple of nights of dripping is trivial next to a burst line.
There is no single number, because it depends on wind, duration, and how exposed the pipe is. As a working guide, sustained temperatures around 20°F put unprotected pipe in vented crawlspaces and exterior walls at real risk, and the risk climbs sharply the longer it lasts.
Because that is the usual pattern. The split often happens while frozen but does not release water until the ice plug melts and pressure returns. That is why the moment you notice you have no water is the moment to act, rather than waiting for things to warm up.
Need someone to actually look at it?
We are a licensed plumber and septic technician based in Ooltewah, serving Hamilton, Bradley and the surrounding counties. Free estimates on every job, and an honest answer about whether you need the work at all.
