How often should you winterize your outdoor hose bibs / taps?

A frozen outdoor tap can burst the pipe and flood a wall.

The split rarely shows itself while frozen. It appears at the thaw, when the ice plug melts and the pipe, now open, discharges inside the wall cavity. People routinely discover it as water coming through a ceiling, and by then it has been running for a while.

1. Disconnect every hose. This alone prevents a large share of failures. A connected hose holds water against the tap and stops it draining, so the trapped water freezes right at the valve.
2. Find and close the interior isolation valve. Most outside taps have a dedicated shutoff inside, often in a basement, crawl space or utility cupboard, near where the pipe passes through the wall.
3. Open the outside tap and leave it open. This drains the section of pipe between the isolation valve and the tap. Leave it open all winter so any residual water has room to expand.
4. Drain the bleed screw if fitted. Many interior isolation valves have a small bleed cap. Open it with a bucket underneath to let the remaining water out.
5. Fit an insulated tap cover. A foam or hard plastic cover over the outside tap adds useful protection, particularly where there is no interior isolation valve.
6. Deal with frost-free taps differently. A frost-free sillcock has a long stem that closes inside the heated envelope. It still must have the hose disconnected to drain, which is the failure people make with them.

• A hose still connected in late autumn, which is the single most common cause
• No water from the outside tap in spring, which suggests it already split
• Bulging or splitting visible on exposed pipework
• Water appearing at a ceiling or wall during the first thaw

• Leaving the hose connected, which defeats every other precaution
• Closing the isolation valve but not opening the tap, so water stays trapped in the section between them
• Assuming a frost-free tap needs nothing: it needs the hose off to drain, and it will split inside the wall if left connected
• Doing it after the first hard freeze rather than before

• Do it before the first frost, not at the first freeze warning
• Taps on north-facing walls in the northern hemisphere freeze first
• Homes left empty in winter should have the supply isolated and drained entirely
• A pipe running through an uninsulated garage or crawl space is at risk well beyond the tap itself

If there is no interior isolation valve for the outside tap, having one fitted is a small job that permanently simplifies every winter afterwards. A plumber can fit one in under an hour.