How To Prevent Frozen Pipes (and Thaw One Safely)

Hard freezes are infrequent here, and that is the problem. Housing in the Dallas area was not built around sustained sub-freezing weather the way housing in Minnesota was: supply lines commonly run through unheated attics, through exterior walls with modest insulation, and across garages, and hose bibs are usually plain exterior spigots. A multi-day freeze finds all of it.

The damage does not happen while the water is frozen. It happens because ice expands and pressure builds in the closed section between the ice plug and a closed faucet until something gives - a split in a copper line, a cracked fitting, a burst washing machine hose. Then it thaws, and the water starts moving through the house.

The pattern differs by housing era, which is why the checklist below covers more than one scenario. In older Dallas, Garland, Mesquite and Richardson homes the vulnerable runs are in uninsulated exterior walls and unheated attics or crawl spaces. In newer two-story Plano, Frisco, McKinney and Prosper builds they are attic lines above the second floor and pipes in garage walls. Nearly every home in the region also has an above-ground irrigation backflow assembly, which cracks readily in a freeze.

The preparation that matters most is done when it is warm and nothing is urgent. All of it is inexpensive and none of it requires a plumber.

1. Find your main water shut-off and make sure it turns. It is usually at the meter box near the street, sometimes in a box on an exterior wall. Clear the lid, check it operates, and show everyone in the house where it is. This single step decides how bad a burst pipe gets.
2. Insulate exposed pipe. Foam sleeves on accessible runs in the attic, garage and crawl space are cheap and effective. Pay particular attention to any pipe within a few feet of an outside wall or an attic vent.
3. Fit insulated covers on exterior hose bibs, and know whether yours are frost-proof. Many North Texas homes have ordinary spigots.
4. Disconnect and drain garden hoses. A hose left attached traps water at the bib, and ice there can split the valve or the pipe behind it inside the wall.
5. Have the irrigation system drained or blown out if it is configured for it, and check the above-ground backflow assembly - it is exposed and it cracks.
6. Seal the obvious drafts: an open crawl space vent, a gap where a line enters an exterior wall, a garage door that does not close fully. Moving cold air is what freezes a pipe that would otherwise be fine.

When the forecast turns, the goal is to keep water moving and warm air circulating in the places pipes actually run.

1. Let a faucet drip on the coldest exterior wall - a slow, steady drip, on the fixture farthest along the run. Moving water resists freezing and the open faucet relieves pressure if a plug does form.
2. Open the cabinet doors under sinks on exterior walls so room air reaches the supply lines behind them.
3. Keep the house heated, and do not turn the thermostat down for a trip - the Insurance Institute for Business and Home Safety's widely cited guidance is to hold a minimum of 55 degrees Fahrenheit even in an unoccupied home.
4. Close the garage door and keep it closed, especially if any plumbing runs along a garage wall or the water heater lives there.
5. If you are leaving for several days in freezing weather, the safest option is to shut off the water at the main and drain the system down by opening the lowest faucets.
6. Leave interior doors open so heat reaches rooms with plumbing on outside walls, and pull back any rug or furniture blocking a vent near one.

The sign is a faucet that gives little or nothing while others work normally. That tells you which run is blocked, and it also tells you there is now a pressurized section behind an ice plug.

Open the affected faucet first - both handles - so meltwater has somewhere to go and pressure can escape as the plug releases. Then warm the pipe from the faucet end back toward the frozen section, so the water that melts can run out rather than being trapped between two plugs. A hair dryer, a heat gun on low, warm towels, or a space heater kept at a safe distance all work.

Never use an open flame - no propane torch, no blowtorch. It is a fire risk in a wall or attic cavity, it can damage the pipe, and on a plastic line it will destroy it outright. If you cannot reach the frozen section, if it is inside a wall, or if you find a split once it thaws, shut the main off and get a licensed plumber on it.

• Open the faucet before you apply any heat
• Warm from the faucet end back toward the ice, never the other way
• Hair dryer, heat gun on low, warm towels or a space heater at a safe distance
• No open flame, ever - fire risk and pipe damage
• Unreachable, inside a wall, or already split: close the main and get matched

Close the main water shut-off immediately - that is the whole reason to have found it in advance. Then cut power to any circuit near standing water at the breaker, and if the water is anywhere near electrical equipment or a gas appliance, treat that as a safety situation first and plumbing second. Open faucets to drain down the remaining pressure in the system, and move what you can out of the water.

Photograph everything before you start cleaning up. It helps the plumber understand what happened and it supports an insurance claim. Then get matched - and do it early, because after a regional freeze every licensed plumber in North Texas is working through a long backlog of burst-pipe calls, and the order requests arrive in matters.

Dallas Best Plumber is a free referral service, not a plumbing company. Tell us what happened and where you are, and we put your request in front of licensed, insured local plumbers who handle emergency work, with a free, no-obligation quote. We do not perform the work or promise an arrival window on anyone else's behalf.