Why a Texas freeze breaks more pipe than a northern one
Houses are built for the climate they are usually in, not the climate they occasionally get.
In cold regions, water lines are kept inside the heated envelope as a matter of course, attics are insulated on the assumption they will be deeply frozen, and hose bibs are frost-proof by default. The house is designed around the problem.
Here, none of that is standard. Supply lines run through vented attics, along uninsulated exterior walls, and through open crawl spaces — all sensible choices for a place that is above freezing 319 mornings a year. Then a hard freeze arrives and every one of those runs is exposed.
Add the pattern: our freezes are short and sharp, often arriving after mild weather, sometimes with wind. People have no reason to prepare in advance, and by the time it is obviously cold there is not much time left.
What actually bursts, in order
Not evenly distributed — a few specific places account for most of the damage.
- Hose bibs with a hose still attached. The single most common burst there is. Water trapped in the hose cannot drain, so it freezes back into the bib and splits it — often inside the wall, where you find out at thaw.
- Attic supply runs. Above the insulation rather than below it, in a space that is the same temperature as outside. When these split, the water lands on the ceiling.
- Pipes in exterior walls, especially on north-facing sides and behind cabinets, where the cabinet door blocks what little warmth the room offers.
- Crawl space and garage runs, particularly to a laundry or a water heater in an unconditioned garage.
- Irrigation backflow preventers, which sit above ground, full of water, entirely exposed.
Worth knowing
Pipes rarely burst at the ice. They burst between the ice and a closed tap, where expanding ice pressurises trapped water with nowhere to go. That is why letting a tap drip works — it is not about keeping water moving, it is about leaving the pressure somewhere to escape.
What to do before a freeze
Most of this is one afternoon in November and costs very little.
Disconnect every hose. This is the highest-value five minutes on the list. Drain them, store them, and fit insulated covers over the bibs.
Insulate exposed pipe in the attic, garage and crawl space. Foam sleeves are inexpensive; pay attention to the joints and elbows, which is where people leave gaps and where the cold gets in.
Shut off and drain irrigation, and insulate the backflow preventer.
Find your main shutoff and make sure it turns. Do this now, in daylight, not by torchlight while water comes through a ceiling. If it is seized, that is a small job today and a disaster later.
Seal draughts where pipes pass through exterior walls. A surprising amount of freeze damage comes down to a gap around a pipe penetration letting cold air blow directly onto it.
During the freeze
Drip the taps that matter — the ones furthest from the heater and any served by pipe running through an unheated space. A steady trickle, not a spray. Both hot and cold.
Open cabinet doors under sinks on exterior walls so room air can reach the pipes. This genuinely helps and costs nothing.
Leave the heat on, even if you are away. Setting it to 55°F while travelling costs far less than one burst pipe.
If a tap stops flowing, act immediately. That is a pipe already frozen and it has not burst yet. Open the tap to relieve pressure, warm the run with a hairdryer or towels soaked in hot water, and work from the tap back toward the frozen section. Never use an open flame or a blowtorch — that is how houses catch fire.
During the thaw, which is when you find out
Most people discover a burst pipe when it thaws, not when it freezes. The ice that split the pipe is also plugging it, so nothing leaks until it melts.
That means the hours after a freeze breaks are the ones to pay attention to. Walk the house: check ceilings for staining, listen for water running with everything off, look under sinks and in the garage, and check every hose bib by turning it on and watching for water appearing inside the wall rather than out of the spout.
If you find one, shut the main off first and worry about which pipe afterwards.
It is also the point at which every plumber in the county is busy at once. Being the person who checked early, rather than the one who found out at midnight, is worth quite a lot.