Know your vulnerable pipes
Pipes most likely to freeze are located in unheated crawl spaces, basements, attics, garages, and exterior walls. In older St. Louis homes, plumbing on north-facing exterior walls is especially at risk during arctic cold snaps.
Outdoor hose bibs, irrigation backflow preventers, and pool plumbing are also vulnerable and should be drained or insulated before winter.
Insulate and seal
Wrap exposed pipes with foam insulation sleeves, especially in crawl spaces and basements. For areas with severe cold, use heat tape with a thermostat on pipes prone to freezing.
Seal air leaks around plumbing penetrations with caulk or spray foam. Cold air blowing on a pipe can freeze it even when the surrounding space is above freezing.
Maintain heat and airflow
Keep your thermostat set to at least 55 degrees Fahrenheit, even when you are away. Open cabinet doors under sinks to let warm air reach pipes on exterior walls.
In extreme cold, let faucets drip slowly. Moving water is less likely to freeze, and the small water cost is far less than a burst-pipe repair bill.
Outdoor plumbing checklist
Disconnect garden hoses, drain hose bibs, and install insulated covers. Shut off and drain irrigation systems, including backflow preventers.
If you have a crawl space, close foundation vents during winter and consider adding a vapor barrier if moisture is a problem. Remove or drain window air conditioners that could let cold air in.
What to do if pipes freeze
If only a trickle comes out of a faucet, the pipe may be frozen. Leave the faucet open and apply gentle heat with a hair dryer, heating pad, or space heater. Never use an open flame.
If you cannot locate the frozen section, if the pipe has already burst, or if multiple fixtures are affected, call a licensed plumber immediately.
Frequently asked questions
At what temperature do pipes freeze in St. Louis?
Pipes can freeze when outdoor temperatures drop below 20 degrees Fahrenheit for several hours, especially if there is wind or poor insulation.
Should I leave faucets dripping in St. Louis winters?
Yes, during extended cold snaps below 20 degrees, a slow drip from faucets on exterior walls can prevent freezing.
Does homeowners insurance cover frozen pipe damage?
Most policies cover sudden and accidental water damage from burst pipes, but not damage from gradual leaks or neglect. Document the damage promptly.
Sources and further reading
The references below informed this guide.
About the author
Nick Cascani is a New York native who has called St. Louis home for the last few years. He believes getting professional home service should be simple and convenient, and he writes these guides to help local homeowners make confident decisions about their HVAC, plumbing, and foundation projects.
Connect with Nick Cascani on LinkedIn