Which pipes are at risk here
Freeze damage in this city concentrates in a few predictable places, because local homes run water through unheated space.
- Attic runs above the insulation
- Garage walls and water heaters in the garage
- Outside hose bibs and the pipe behind them
- Exposed pipe under the house or along an exterior wall
- Irrigation backflow preventers above ground
Before the cold arrives
- Cover the hose bibs
Take the hose off and fit an insulated cover. A hose left connected traps water in the bib and splits it.
- Insulate exposed pipe
Foam sleeves on attic, garage and exterior runs. Tape the seams so wind cannot get in.
- Wrap the backflow preventer
Insulate the irrigation backflow assembly, or shut it off and drain it for the season.
- Know your shut-off
Check the main valve turns freely while the weather is fine.
During a hard freeze
Let a thin, steady drip run from the tap furthest from where the water enters the house, so water keeps moving through the coldest run. Open the cabinet doors under sinks on exterior walls so room heat reaches the pipe. Keep the heating on overnight even if you are away, and if you are leaving for days, shut the water off at the main.
If a pipe has already frozen
No water at one tap after a freezing night usually means ice in that line. Open the tap so melting water has somewhere to go, and warm the pipe with a hair dryer or towels soaked in hot water, working from the tap back toward the frozen section. Never use a blow torch. If the pipe has already split, shut the water off at the main and call us — the damage shows up as soon as the ice melts.
Questions people ask
How cold does it have to be here for pipes to freeze?
Uninsulated pipe in an attic or garage can freeze once the air outside sits below freezing for several hours, especially with wind. Long overnight freezes do most of the damage in San Antonio.
Does dripping the tap really help?
It helps because moving water is harder to freeze and because an open tap relieves the pressure that actually splits a pipe. A thin steady trickle is enough.
My water heater is in the garage — is that a problem?
It is a common spot for freeze damage because the supply lines sit in unheated space. Insulate the lines and keep the garage door closed during a freeze.