How to protect your pipes in a Houston freeze

What 2021 taught Houston

In February 2021, Houston spent several days below freezing with much of the city without power. Attics dropped to outdoor temperature. Pipes froze, then burst when they thawed, and because the water was off at the plant for many areas, the flooding started when service came back. Plumbers were booked for weeks. Fittings and PEX sold out. People who had never thought about their pipes learned where they were the hard way.

The lesson is not that Houston needs northern plumbing. It is that a few specific pipes need protection, and the protection is cheap if you do it before the freeze.

The pipes at risk in a Houston house

• Attic lines. Many Houston homes run supply lines through the attic. The attic is not heated. In a long freeze with no power it reaches outdoor temperature.
• Exterior wall lines. Kitchen and bathroom sinks on outside walls, especially in older houses with little insulation.
• Hose bibbs. The outside faucets, and the short line behind them in the wall.
• Outdoor tankless water heaters. Most have built-in freeze protection, but it needs electricity. In 2021 the power went out and the heat exchangers froze.
• Irrigation backflow preventers. The brass assembly above ground near the meter.
• Pool equipment and any pipe in an unheated garage.

Before the freeze

1. Find the main shutoff and test it. Usually near where the line enters the house, often by the front hose bibb, in the garage, or at the meter box near the street. If the valve will not turn, have a plumber replace it now, not during the freeze.
2. Insulate exposed lines. Foam pipe sleeves from any hardware store, taped at the seams. Do the attic lines you can reach, the hose bibb lines, and the irrigation backflow.
3. Cover hose bibbs. Disconnect hoses first. A foam cover or a wrapped towel in a plastic bag works.
4. Drip the faucets. Both hot and cold, on the faucets farthest from where the water enters. A steady drip, not a stream.
5. Open the cabinet doors under sinks on exterior walls so room heat reaches the pipes.
6. Keep the heat on, even if you leave. Set it no lower than the mid 60s.
7. Protect the tankless. Keep power to it. If the power is out and the freeze is long, follow the manufacturer’s drain procedure or isolate and drain the unit.
8. If you leave town for days, consider shutting the main and opening the faucets to drain the lines.

Insulation versus heat tape

Foam insulation slows heat loss but does not add heat. In a short freeze it is enough. In a multi-day freeze with no power, an attic line in foam will still freeze eventually. Heat tape is an electric cable that warms the pipe. It works only with power, must be listed for the use, must not be overlapped, and must not be covered with the wrong insulation. Read the label, and do not use it on PEX unless the product says it is rated for it. For most Houston homes, foam on the exposed lines plus dripping faucets is the practical answer.

After a pipe bursts

1. Close the main shutoff. If you cannot, close the valve at the meter with a meter key or a wrench.
2. Open a faucet at the lowest point to drain the pressure.
3. If you are draining the house, turn off the water heater. A gas heater with no water in it will damage itself. An electric one will burn out the elements.
4. Turn off electricity to any area where water is near outlets or fixtures.
5. Photograph everything before cleanup, for the insurance claim.
6. Call a licensed plumber. Expect a wait during a citywide event, and expect emergency rates.
7. Dry the house fast. Mold can begin within 24 to 48 hours.

A frozen pipe that has not burst can often be thawed with a hair dryer or warm towels, starting at the faucet end. Never use an open flame.

Who to call, and who showed up in 2021

Plumbing repairs in Texas require a license from the Texas State Board of Plumbing Examiners. During the 2021 storm the state temporarily relaxed some rules so out-of-state plumbers could work under Texas supervision. What also arrived was a wave of unlicensed operators charging cash prices for repairs with no permit, no warranty and no one to call when the fitting failed a month later. Some of the work was fine. Much of it was not, and the companies were gone by spring.

Before you pay anyone to open a wall:

• Ask for the license number and look it up.
• Get the repair in writing, with the pipe material and the warranty.
• Pay on completion, not up front.
• If an electrician or HVAC company is also involved, the same rule applies: licensed with the state, in writing, paid when done.

The houses that came through 2021 best were not the ones with the most insulation. They were the ones where someone knew where the shutoff was.