How to Winterize Outdoor Faucets and Prevent Frozen Pipes

Water expands by about 9% when it freezes, and a pipe that bursts in January often cracked weeks earlier in the first hard frost. Ten minutes in the fall prevents it. Here is exactly what to do, in the order to do it, including how to tell if you already have a frost-free faucet.

Why outdoor faucets burst

Ice takes up more space than liquid water, which is why ice floats (the USGS explains this in its water density guide). Trapped in a pipe, expanding ice raises pressure in the water between the ice and a closed valve until something gives. The split often happens inside the wall where you cannot see it, and you discover it only when you use the hose in spring and water pours into the basement.

When to winterize

Aim to finish before the first forecast hard freeze, typically when nights are expected to fall below about 28°F (−2°C). In the northern US, UK and much of Canada, that means October or early November. Write it on the calendar alongside clearing gutters.

The 6-step winterizing checklist

• Disconnect and drain all garden hoses
• Find the indoor shut-off valve for each outdoor faucet
• Close the indoor shut-off valve
• Open the outdoor faucet to drain it (leave it open)
• Open the small bleeder cap on the indoor valve, if it has one, to drain the remaining water
• Fit an insulated faucet cover outside

1. Disconnect hoses

A hose left attached holds water in the faucet, even in a frost-free model, which defeats its design. Drain hoses, coil them and store them in a garage or shed so the rubber does not crack.

2. Find the shut-off valve

In most North American houses with a basement or crawl space, each hose bib has a dedicated shut-off valve on the pipe a few feet inside the wall. Follow the pipe from where the faucet passes through the wall. It may be a gate valve (round handle) or a quarter-turn ball valve (lever).

3. Close it, then drain the faucet

Close the indoor valve, then go outside and open the faucet fully. Water will run for a few seconds and stop. Leave the outside faucet open all winter so any remaining water has room to expand.

4. Open the bleeder cap

Many shut-off valves have a small brass cap on the side. With a bucket underneath, unscrew it to let trapped water drain from the pipe section, then replace it.

Do you have a frost-free faucet?

A frost-free (freeze-proof) sillcock has a long stem, so the actual valve sits 6 to 12 inches or more inside the heated wall. Clues: the handle is perpendicular to the wall on a long body, and when you turn it off, water keeps draining from the spout for a few seconds. These still need hoses disconnected, but usually no indoor shut-off.

Protect other vulnerable pipes

• Insulate pipes in unheated spaces: crawl spaces, garages, attics and exterior walls. Foam pipe sleeves are cheap and slip on.
• Seal gaps where pipes enter the house with caulk or spray foam to block cold drafts.
• Blow out or drain irrigation (sprinkler) systems per the manufacturer's instructions, or hire the installer.
• In very cold snaps, the American Red Cross suggests opening kitchen and bathroom cabinet doors so warm air reaches pipes, and letting a faucet drip on exposed pipes, since moving water is less likely to freeze.
• Keep the thermostat set to the same temperature day and night during extreme cold, and do not set it below about 55°F (13°C) when you travel.

What to do if a pipe freezes

Signs: a faucet produces only a trickle or nothing in cold weather, or you see frost on a pipe.

1. Keep the faucet open so melting water can flow out and relieve pressure.
2. Apply gentle heat to the frozen section: a hair dryer, a heating pad, or towels soaked in hot water. Work from the faucet back toward the frozen section.
3. Keep heating until full water pressure returns.
4. Check all other faucets; if one froze, others may have too.

Know where your main shut-off is

Before winter, find your home's main water shut-off (often where the water line enters the basement or near the water heater, sometimes in an outdoor box near the street). Make sure it turns, and show everyone in the house. If a pipe bursts, closing it fast is the difference between a mop and a renovation.

Spring: turning it back on

After the last hard frost, close the outside faucet, open the indoor valve slowly, and then open the outdoor faucet while someone watches the indoor pipe for drips. A leak or a weak spray from the wall area is a sign of a split pipe that froze over winter.

Renters and condos

If you rent, ask your landlord or building manager who handles winterizing, and where the shut-offs are. Many leases make the landlord responsible for plumbing but expect tenants to disconnect hoses and report problems. In apartments, the risk is usually pipes in exterior walls or unheated parking levels. Keep the heat on when traveling, open sink cabinet doors on exterior walls during severe cold, and know where your unit's water shut-off is. Frozen-pipe damage is far easier to prevent than to argue about afterward.

Insurance note

Home insurance policies vary on frozen pipe damage, and some exclude it if the home was left unheated or unattended. Read your policy's wording before winter and document your winterizing with a photo or two.

Quick fall timeline

Early autumn: buy faucet covers and pipe insulation. Before the first hard freeze: disconnect hoses, close and drain. Mid-winter cold snaps: open cabinet doors on exterior walls and keep the heat steady.