Shut off outdoor faucets before the first freeze

What actually breaks

Water is one of the few things that expands as it freezes. Colorado State University Extension's irrigation winterization sheet puts the physics in numbers: water contracts down to 39°F, then expands as it turns to ice at 32°F, gaining about one-eleventh of its volume. Eleven cubic feet of water become roughly twelve cubic feet of ice. That force splits whatever still holds the water — a hose bib, the pipe in the wall, or the supply on the heated side of it.

The American Red Cross lists outdoor hose bibs among the pipes that freeze most often, alongside sprinkler lines and anything running through an unheated basement, crawl space, attic or garage.

The four moves

Red Cross frozen-pipe guidance is the sequence. Illinois Extension adds the bleeder so the indoor shutoff actually empties the line instead of trapping a vacuum.

1. Remove, drain and store every hose. Illinois Extension: if the hose stays attached, water can remain in the line and ice can progress back into the spigot and into the house. Store the empty hose somewhere sheltered.
2. Close the indoor shutoff that supplies that bib. Look on the interior wall opposite the faucet.
3. Open the bleeder on that shutoff if it has one. Illinois Extension: close the valve, then open the bleeder to empty the waterline. A bucket under the cap catches what comes out.
4. Open the outdoor bib and leave it open. Red Cross: open the outside hose bibs to drain, then keep the outside valve open so leftover water can expand without breaking the pipe.

Frost-proof is not hose-proof

A frost-proof sillcock puts the valve seat inside the heated part of the wall so the exposed tube can drain when you shut it off. That only works if nothing is blocking the nozzle. Woodford Manufacturing's troubleshooting for a wall faucet that leaks from inside the wall after winter is a split tube caused by freeze-up — because the hose, an add-on vacuum breaker, or a quick-disconnect was left on the nozzle and the faucet could not drain. Improper pitch at install does the same thing.

Illinois Extension is blunt about the marketing name: even though they are called frost-proof, do not assume the spigot will not freeze. It depends on how cold it gets and how well the wall cavity is insulated. A shutoff with a bleeder on each line is the backup they recommend for peace of mind. New spigots also usually include an anti-siphon feature so hose water cannot be drawn back into the house supply — that is a different job from freeze protection, and an add-on vacuum breaker is exactly the attachment Woodford says can stop a frost-proof faucet from draining.

What the sources actually say

The sequence and the “leave it open” rule are the American Red Cross. The bleeder and the hose-into-the-house path are Illinois Extension. The expansion numbers are Colorado State University Extension.

The frost deadline, not October

This job shares a trigger with sprinkler winterization: first frost, which is weeks apart across the country and a different week every year. If you are already outside for gutters or leaf mulching, walk the house and count the bibs — including the one behind the AC condenser and the one on the garage.

Where to stop and call someone

The bib itself is a five-minute job. Hand it to a plumber if:

• You cannot find an indoor shutoff for a bib, and you are not willing to shut the whole house off to drain that one line.
• The faucet already leaks from inside the wall when you turn it on — Woodford's description of a split tube after a freeze. That is a replacement, not a drain.
• The spigot is the old short-body kind Illinois Extension says to swap for a frost-proof one. Cutting into the supply is a plumbing repair.
• You open the indoor valve in spring and water shows up where it should not — inside the wall, the basement ceiling, or around the sill.

A service call before the freeze is cheaper than opening the wall in spring.

Questions people actually ask

When should I shut off outdoor faucets?

Before the first freeze, not on a calendar date. That is the same frost deadline as sprinkler winterization, and it moves by weeks between the Upper Midwest and the Mid-Atlantic. Our regional pages track soil temperature daily as that window opens.

I have frost-proof faucets. Do I still have to do this?

You still have to take the hose off. Woodford's own troubleshooting for a split tube is a hose, an add-on vacuum breaker, or a quick-disconnect left on the nozzle — anything that stops the faucet from draining. Illinois Extension adds that frost-proof spigots can still freeze depending on how cold it gets and how well the wall cavity is insulated.

Why leave the outdoor faucet open all winter?

The American Red Cross's frozen-pipe guidance is to open the outside hose bibs to drain, then keep them open so any water still in the pipe can expand without breaking it. A closed bib traps that leftover volume.

Where is the indoor shutoff?

On the interior wall opposite each outdoor bib — basement, crawl space, or utility room. Illinois Extension's peace-of-mind upgrade is a shutoff with a bleeder: close the valve, then open the bleeder so the line actually empties instead of sitting there under vacuum.

Is this the same job as winterizing the sprinklers?

Same deadline, different pipe. The irrigation system is a buried network that usually needs compressed air. The hose bib is a short run through the wall. Skipping either one can put ice in a line that feeds the house.

Sources

• American Red Cross — Preventing & Thawing Frozen Pipes: hose bibs as a freeze risk; remove, drain and store outdoor hoses; close indoor supply valves; open outside bibs to drain and leave them open so remaining water can expand.
• Illinois Extension — How to winterize outdoor plumbing: ice traveling from a connected hose back into the house; frost-proof still can freeze; shutoffs with bleeder valves; anti-siphon on new spigots.
• Woodford Manufacturing — Model 14 wall faucet troubleshooting: split tube from a freeze caused by a hose, add-on vacuum breaker or quick-disconnect left on the nozzle.
• Colorado State University Extension — Preparing your sprinkler system for winter: expansion of 1/11 as water turns to ice at 32°F after contracting to 39°F.

General information, not advice for your specific plumbing. A leak inside the wall is a plumber's job.