Frozen and Burst Pipes in North Texas: Before, During and After a Freeze

How cold does it have to get before North Texas pipes burst?

There is no single temperature. Risk climbs when the air stays below freezing for a long stretch rather than dipping for one night, and February 2021 showed why: about 295 consecutive hours below freezing at DFW, bottoming out at minus 2 degrees F on 16 February. Wind and power loss make it worse.

A single frosty night rarely does much here. What breaks pipes is duration, because cold has to work its way through brick veneer, attic insulation and a garage wall before it reaches water. Once the air has been below freezing for a day or two, the parts of a house that never see the furnace start to equalise with the outside.

February 2021 is the storm every North Texas homeowner now measures against. It ran from 13 to 17 February 2021, DFW recorded minus 2 degrees F on 16 February, the second coldest reading in its history after minus 8 degrees F in February 1899, and the airport came out of it having spent about 295 consecutive hours, around twelve days, at or below freezing. About 4.5 million Texas homes and businesses were without power at the peak and North Texas water systems lost pressure, so houses went cold for days and then leaked together when the thaw spread.

That combination is the real hazard, not the thermometer alone. A heated house survives a cold night. A house with no power, no heat and falling water pressure is a house where the pipes in the attic are the same temperature as the air outside.

Which pipes freeze first in a Dallas house?

The ones outside the heated envelope. In a typical Dallas house that means supply lines crossing a vented attic to upstairs baths and attic water heaters, lines in exterior walls behind brick veneer, uninsulated garage walls, hose bibs with a hose attached, and the irrigation backflow assembly standing in the front yard.

Vented attics are the local signature. A Dallas attic is designed to let hot summer air out, which means it also lets January air straight in, and a copper or PEX run crossing that space has only its own insulation between it and the weather. Many of those attics also hold the air handler and a tank water heater, so a break up there drains through a finished ceiling instead of onto a garage floor.

Brick veneer hides the second group. Water lines serving a kitchen sink or a hall bath often run in the stud bay just inside the brick, and that cavity has an air gap behind the masonry. Nothing about it looks exposed, which is exactly why those breaks are the hardest to find afterwards.

The irrigation backflow assembly is the one most people forget. It sits above the ground near the front of the house, usually with nothing over it, and the brass body cracks neatly. It wastes water into the yard rather than the house, so it tends to be discovered on the first water bill rather than on the first night.

• Attic supply runs feeding upstairs bathrooms, and the cold water line into an attic tank water heater
• Lines in exterior walls, particularly on the north and west sides behind brick veneer
• Pipes in an uninsulated or unheated garage wall, including the laundry box and the water heater closet
• Hose bibs on the brick, especially with a hose still attached, because the hose holds water against the valve
• The above-grade irrigation backflow assembly in the front yard, which has no insulation at all
• Lines in an unconditioned utility room, a detached garage or a converted porch
• Fire sprinkler lines in some older apartment buildings and small commercial spaces, where one break reaches several units

What should you do before a hard freeze arrives?

Work backwards from the forecast. A week out, deal with hoses, bib covers and irrigation. A day out, open cabinets on outside walls and set the thermostat. During the freeze, keep the garage closed and the house heated. On the thaw, walk every ceiling and every wall base looking for the first stain.

None of this needs a contractor. A hose bib cover costs a few dollars, a meter key costs a little more, and the single most useful thing on the list is knowing where your main shut-off is before you need it in the dark. In many Dallas-area houses that valve sits in the street-side meter box at the curb, and some houses also have one where the line enters the house or the garage wall. Go and look now, while it is daylight.

If you are leaving town in a freeze week, the decision is between heat and drainage. Leaving the thermostat on is the simpler option for a short trip. For a longer absence, shutting the main valve and draining the lines from the lowest fixture removes the water that would otherwise do the damage.

Why does the water arrive after the cold has gone?

Freezing water expands and builds pressure in the closed section between the ice plug and a shut tap, and that pressure splits the pipe. While the plug is still frozen it seals its own crack. When the ice melts, the split opens to full house pressure and water runs, often from a point nowhere near where the pipe froze.

This is the single most useful thing to understand about a North Texas freeze, because it explains the timing that catches people out. The cold snap ends, the sun comes out, everybody relaxes, and two days later a ceiling in a back bedroom starts to bulge.

It also explains why the damage can be so far from the break. An attic split drains along the top plate of a wall, finds a seam in the drywall and comes down somewhere else entirely. In a two-storey house it can run down inside an interior wall and appear at a ground-floor baseboard.

The practical consequence is that a house which came through a freeze with nothing visible is not automatically fine. If a tap ran dry during the cold and then came back, something was frozen. Walk the house with a torch for a few days after, and keep an eye on the meter with every fixture closed.

How do you thaw a frozen pipe without making it worse?

Open the tap the pipe feeds so melting water has somewhere to go, then warm the frozen section slowly with a hair dryer, a heat lamp or warm towels, working from the tap back toward the cold spot. Never use a torch or any open flame. Stop and call a plumber if water appears.

Working from the fixture back matters. If you heat the middle of an ice plug first, the meltwater has nowhere to escape and the pressure goes up rather than down. An open tap gives it an exit and tells you the moment flow returns.

Open flame is the one rule with no exceptions. A torch in an attic full of blown insulation, or against a wall cavity you cannot see into, is how a water problem becomes a fire. The same goes for leaving a space heater unattended against a wall base.

If you cannot reach the frozen section, or it is in a wall or an attic you are not comfortable in, stop. Shut the main valve and wait for a plumber. A pipe that thaws on its own while the water is off does far less damage than one that thaws under pressure.

A pipe just burst. What are the first ten minutes?

Shut the main valve, stay off wet floors near outlets and appliances, and turn power off to the wet area only if you can reach the panel safely. Then photograph every room before anything is moved, lift what you can off the floor, and call for extraction while you call a plumber.

Call (833) 490-5225 at any hour of any night. Someone answers, the emergency-stage price is explained before any equipment runs, and a crew is dispatched as fast as one is available. In a regional freeze that honesty matters: every crew in North Texas is working the same backlog in the same week, and nobody can promise you a time.

• Close the main shut-off. In many Dallas houses it is in the street-side meter box and needs a meter key; some houses have a second valve at the wall or in the garage
• Keep everyone, children and pets included, out of standing water near outlets, cords and appliances
• Cut power to the wet area at the panel only if you can get there without standing in water
• Photograph and video every affected room before anything is moved, including inside cabinets
• Lift furniture legs onto blocks or foil, take rugs off wet carpet, and get boxes off the floor
• Open the cabinet under a wet sink and pull what is stored there out to dry
• Call for water removal and drying, and separately call a Texas-licensed plumber for the pipe itself

When does a freeze not need a restoration crew?

Often. A hose bib that split outside with nothing wet in the wall, an irrigation backflow assembly cracked in the yard, a pipe that froze and thawed with no leak, or a small puddle wiped off tile within minutes are all plumbing or do-nothing situations rather than drying jobs.

What does need a call is water that has reached porous materials. Carpet and pad, drywall, cabinet bases, insulation, engineered wood and the bottom plates of walls all hold water long after the surface looks dry, and a household fan will not pull it back out of a wall cavity.

The test most people can apply themselves is smell and time. If a room was wet, has been drying for two days with fans, and smells more musty rather than less, something inside the assembly is still wet. That is the point where a moisture meter earns its keep.

• A cracked hose bib or irrigation backflow assembly that leaked into the yard, with no damp drywall or stain indoors: a plumber or irrigation contractor, and nothing to dry
• A pipe that froze, was thawed carefully and held pressure afterwards: watch it, and have a plumber look if it froze more than once
• A small amount of clean water on tile or sealed concrete, towelled up straight away before it reached carpet, drywall or cabinets
• A water heater pan that caught a drip and drained where it was meant to
• A single wet spot in a garage on bare concrete, with nothing behind the wall board

What does the cleanup actually involve after a freeze leak?

A plumber repairs the line while the crew extracts water, maps hidden moisture with meters and thermal tools, opens what has to come out, and sets air movers and dehumidifiers. Readings are rechecked until materials test dry. Repairs to ceilings, drywall and flooring are quoted after drying, not before.

Attic leaks are the ones with the most removal. Wet blown insulation loses its value and holds water against the ceiling board, so it usually comes out, and a textured ceiling that has sagged is cut rather than patched. Down at floor level the pad under wet carpet is usually disposed of, while the carpet above it can frequently be dried and put back when the water was clean.

Documentation is a bigger part of a freeze job than of most others, because so many houses are claiming at once. Photos, moisture readings and drying logs can be handed to your insurer, and your insurer decides the claim under your own policy. Texas policies generally treat sudden and accidental water damage differently from a slow leak, which the Texas water damage insurance guide sets out in detail.

One last piece of local honesty. After a freeze, out-of-town crews arrive in North Texas looking for work, and some of them offer to cover your deductible. Texas Insurance Code Chapter 707 makes that illegal: you pay your deductible, and a contractor may not waive, rebate, absorb, credit or offset it. Treat the offer as a reason to keep looking.