At What Temperature Do Pipes Freeze? A Colorado Homeowner's Guide

In Littleton, a winter cold snap can keep temperatures below 20°F for days at a time. If you're dealing with a pipe that has already split, start with burst pipe water damage repair in Littleton. Reestorian can connect you with a local provider for the cleanup. If not, this guide explains exactly when pipes freeze, which ones go first and how to tell if one has frozen.

This is general information. Every home is different, and a licensed plumber can tell you how well your pipes are protected.

At what temperature do pipes freeze?

Pipes start freezing at outdoor temperatures around 20°F or colder. Texas A&M AgriLife Extension says water pipes can freeze and burst when the outside temperature reaches 20°F or below. The International Code Council cites the Insurance Institute for Business and Home Safety (IBHS) for the same point: unprotected pipes begin to freeze when outdoor temperatures drop to 20°F.

Why not 32°F? Because most pipes sit inside a house that is warmer than the outdoors. The wall, insulation and indoor air slow the cold down. A pipe only freezes when the water inside it actually drops to 32°F, and that takes colder outdoor air, more time or a gap that lets cold air reach the pipe.

Which pipes freeze first in Colorado homes?

Pipes freeze first where cold air reaches them and household heat doesn't. The American Red Cross lists these as the highest-risk spots:

• Outdoor hose bibs, pool supply lines and sprinkler lines
• Supply pipes in unheated areas, such as basements, crawl spaces, attics and garages
• Pipes in kitchen and bathroom cabinets on outside walls
• Pipes along exterior walls with little or no insulation

Denver Water adds pipes routed through an unheated attached garage and exposed pipes behind sink access doors. In many Littleton homes, that means the line to an upstairs bathroom above the garage, a kitchen sink on an outside wall or the supply line where it enters the basement.

How long does it take for pipes to freeze?

There is no single answer. It depends on how cold it is, how long it stays cold and how exposed the pipe is. A copper line in a drafty garage wall can freeze overnight in single-digit cold. A pipe in an insulated interior wall might never freeze. The longer the cold lasts, the more heat drains out of walls and crawl spaces, so the second and third nights of a cold snap are often when trouble starts.

What temperature do pipes burst?

There's no separate bursting temperature. Pipes burst after they freeze, so the same 20°F danger point applies. It's not the ice itself that usually splits the pipe. IBHS research cited by the International Code Council explains that pipes often burst where little or no ice has formed. When ice blocks a pipe, water trapped between the blockage and a closed faucet has nowhere to go. As more ice forms, pressure builds until the pipe or a fitting gives way.

That's why letting a faucet drip helps. An open faucet relieves pressure in the line, even if some ice forms.

How do you know if your pipes are frozen?

Signs a pipe has frozen:

• Only a trickle, or nothing, comes out when you open a faucet. The Red Cross says this is the main warning sign.
• Frost or ice is visible on an exposed pipe.
• The toilet doesn't refill after flushing.
• One faucet works and another doesn't, which points to a frozen section on one branch.
• A bulge or crack appears on a pipe, which means it may leak when it thaws.

If you suspect a frozen pipe, check near exterior walls and where the water service enters through the foundation, as the Red Cross suggests.

What to do if your pipes freeze

1. Open the faucet the pipe supplies so water can flow as the ice melts.
2. Find your main shutoff before you start. Denver Water advises testing the shutoff first so water doesn't gush out when the pipe thaws.
3. Apply gentle heat. Use an electric heating pad, a hair dryer, a space heater kept away from anything flammable, or towels soaked in hot water.
4. Never use an open flame. The Red Cross warns against blowtorches, kerosene or propane heaters and charcoal stoves.
5. Keep heating until full pressure returns, then check other faucets in the house.

Call a licensed plumber if you can't find the frozen section, can't reach it or can't thaw it.

How to protect your pipes when it gets below 20°F

• Keep the thermostat steady day and night
• Open kitchen and bathroom cabinet doors on outside walls
• Keep the garage door closed if water lines run through it
• Let cold water drip from faucets served by exposed pipes
• Disconnect, drain and store garden hoses
• Keep the heat no lower than 55°F if you leave home, as the Red Cross recommends; Denver Water suggests above 65°F for trips of several days

The full checklist is in the guide on how to prevent frozen pipes.

Littleton and the south metro: why cold snaps matter here

Littleton averages about 65 inches of snow a year, but snow isn't the main risk to pipes. The risk is the stretch of days when highs stay below freezing and lows fall into the single digits. Many south metro homes have plumbing in places that are hard to keep warm: bonus rooms over garages, kitchens on outside walls and crawl spaces under additions. Homes at higher elevations, like Castle Rock at about 6,224 feet and the foothill neighborhoods of Ken Caryl, can see colder nights than central Littleton.

Insurance basics for frozen pipes

The Colorado Division of Insurance says burst pipes and the water damage they cause are generally covered by homeowners and renters policies. Many policies exclude freeze damage when a home wasn't heated or the water wasn't shut off and drained, so read your policy before winter travel. The guide does homeowners insurance cover frozen pipes? covers the details.

Related reading: If a pipe has already split, follow the steps in what to do when a pipe bursts. For prevention before the next cold snap, see how to prevent frozen pipes in a Colorado winter.

When should you call a water damage professional?

Call a plumber to fix a frozen or cracked pipe. Call a water damage professional when:

• Water has run from a split pipe into walls, ceilings or floors
• A ceiling is stained, sagging or dripping
• Water reached carpet, a finished basement or the floor below
• You can't tell how far the water spread

Burst pipe in Littleton? Call (928) 394-5135 to reach a local water damage provider.