How to Winterize Outdoor Plumbing

Why Winterization Matters

Outdoor plumbing — hose bibs, irrigation systems, outdoor kitchens, and pool plumbing — is highly vulnerable to freeze damage because it is exposed to outside temperatures without the heating benefit of being inside the home's building envelope. Water that freezes inside these pipes expands with tremendous force, cracking pipes, fittings, and valves. The resulting damage is often not discovered until spring when the water is turned back on, potentially causing significant flooding and water damage.

Winterizing Hose Bibs

Disconnect all garden hoses from outdoor faucets — a connected hose traps water in the faucet body, even frost-free models, causing them to split. If your outdoor faucets have separate interior shut-off valves (usually located in the basement near where the pipe exits the wall), close them and open the outdoor faucet to drain residual water. Leave the outdoor faucet open so any remaining water can expand without bursting the pipe. For added protection, install foam faucet covers (available at hardware stores for a few dollars each) over all outdoor faucets.

Irrigation System Winterization

Irrigation (sprinkler) systems must be blown out with compressed air before freezing weather. Turn off the water supply to the irrigation system at the main shut-off valve. Open the drain valves if your system has them. Using an air compressor set to no more than 80 psi (50 psi for polyethylene pipe), blow air through each irrigation zone individually until no more water comes out of the sprinkler heads — typically 2 to 3 minutes per zone. Start with the zone farthest from the compressor connection. Do not over-pressurize, as this can damage pipes and sprinkler heads.

Additional Outdoor Plumbing

Outdoor kitchens, pool plumbing, and fountain systems also require winterization. Drain all water from outdoor kitchen supply lines and appliances. For pools, lower the water level below the skimmer, drain the pump and filter, and blow water from the plumbing lines using a shop vacuum or compressor. Add non-toxic pool antifreeze to the skimmer, return lines, and main drain. Cover the pool to prevent debris accumulation. For decorative fountains, drain the basin and pump completely, remove the pump, and store it indoors. Cover the fountain to prevent water collection that could freeze and crack the basin.