How to Know at What Temperature Pipes Freeze

The Winter Threat to Your Home’s Plumbing

Understanding at what temperature do pipes freeze is critical for protecting your Chicago home from costly winter damage. Here’s what you need to know:

Quick Answer:

• 32°F (0°C): Water begins to freeze, but pipes are usually safe
• 20°F (-6°C): The danger zone where pipes are most likely to freeze
• Duration matters: Uninsulated pipes can freeze in 6-8 hours; insulated pipes may freeze in under 6 hours when temperatures drop below 20°F

After a chilly night, nothing ruins your morning quite like turning on the faucet and getting nothing but silence. No running water means you’ve likely got a frozen pipe—and if you don’t act fast, that frozen pipe can burst and cause thousands of dollars in water damage.

Why Do Pipes Freeze?

Why pipes freeze is simple: When temperatures drop, the water inside your pipes freezes and expands. This expansion creates pressure that can exceed 2,000 pounds per square inch, enough to crack even metal pipes. The burst doesn’t happen where the ice forms—it happens between the ice blockage and your faucet, where pressure builds with nowhere to go.

In Chicago, where winter temperatures regularly dip well below freezing, frozen pipes are a real and expensive threat. The average cost to repair a burst pipe is $500, but the water damage that follows can easily cost $5,000 or more in property repairs, not to mention the disruption to your daily life.

The good news? Frozen pipes are preventable when you know what temperature puts your plumbing at risk and take the right steps before the cold sets in.

I’m Ryan Majewski, General Manager of Chicago Water & Fire Restoration, and I’ve spent over a decade helping Chicago-area property owners recover from water damage caused by frozen and burst pipes. Through my work restoring hundreds of properties and managing restoration projects across the Midwest, I’ve learned that knowing at what temperature pipes freeze—and acting on that knowledge—is the difference between a safe winter and a restoration emergency.

Step 1: Understand at What Temperature Pipes Freeze

While water freezes at 32°F (0°C), your home’s plumbing is more resilient. However, there is a temperature threshold where the risk becomes severe. Knowing this is the first step to protecting your property during the frigid winters we experience across Chicago, Illinois, Wisconsin, and Indiana.

Your pipes usually won’t freeze unless the ambient temperature dips to 20°F (-6°C) or lower. This is the “danger zone” for residential plumbing, where cold can penetrate the pipe and freeze the water inside, especially if pipes are exposed or poorly insulated.

The duration of cold exposure is just as critical as the temperature. A quick dip below freezing might not cause issues, but prolonged exposure—six to eight consecutive hours—can be enough to freeze an uninsulated pipe.

Wind chill is another significant factor. It doesn’t lower the air temperature, but it accelerates heat loss. A strong winter wind can make pipes in a crawl space or on an exterior wall freeze much faster. The American Red Cross provides excellent guidance on preparing for and thawing frozen pipes, emphasizing the importance of understanding these conditions. You can find more helpful information on Preventing & Thawing Frozen Pipes.

4 Key Factors That Influence at What Temperature Pipes Freeze

Outdoor temperature isn’t the only factor. Several variables influence how quickly your plumbing becomes vulnerable, helping you pinpoint at-risk areas for preventative measures.

• Pipe Location: Pipes in unheated areas like basements, attics, crawl spaces, and garages are most susceptible as they lack consistent warmth. Pipes running along exterior walls, especially with poor insulation, are also prime targets. Even pipes under sinks against an exterior wall can freeze.
• Lack of Insulation: Insulation is a crucial barrier that slows the transfer of cold to the water inside a pipe. Without it, water freezes quickly. This applies to both the pipes themselves and the general insulation of the spaces they occupy, like attics or crawl spaces.
• Pipe Material: Different materials conduct cold at varying rates. Copper pipes cool down and freeze faster than PEX (cross-linked polyethylene) pipes. While PEX is more flexible and less likely to burst, it can still freeze.
• Drafts and Air Leaks: Cold air infiltrating through gaps around wiring, dryer vents, or where pipes enter your home can create localized freezing points. Sealing these air leaks is a simple, effective preventative measure. For more specific advice on protecting your plumbing in our climate, check out our guide on How to Keep Pipes from Freezing in a Chicago Winter.

How Long It Takes for Pipes to Freeze at a Certain Temperature

The speed at which pipes freeze is critical. For uninsulated pipes, the process can be quick. In temperatures between 20°F and 32°F, it typically takes around 6 to 8 hours for a pipe to freeze solid.

When temperatures plummet to 20°F or below, the timeline shortens dramatically. In such frigid conditions, pipes can freeze in as little as two hours. Even insulated pipes can freeze in under six hours at these extreme temperatures, as insulation only slows heat loss, it doesn’t add heat.

Chicago’s climate, with its prolonged sub-zero temperatures and strong winds, creates a perfect storm for frozen pipes. Understanding these timelines highlights the urgency of winterizing your home. For a deeper dive into local risks, read our article on At What Temperature Do Pipes Freeze in Chicago?.

Step 2: Identify the Signs of Frozen and Bursting Pipes

Even with the best efforts, pipes can freeze. The good news is they don’t always burst immediately, giving you time to act. Recognizing the signs early is key to preventing extensive damage.

The most obvious sign of a frozen pipe is a lack of water, or only a trickle, coming from a faucet. If you turn on the tap and nothing happens, or the flow is significantly reduced, a frozen pipe is the likely culprit. This often happens first with faucets on exterior walls or in unheated areas.

Other indicators include:

• Frost on Exposed Pipes: If you can see your pipes in an unheated basement, crawl space, or garage, check for frost on their exterior. This is a clear visual cue that the water inside is freezing.
• Strange Smells from Drains: An unusual odor coming from your drains or faucets can indicate an ice blockage, as water and waste might be backing up.
• Banging or Gurgling Sounds: If you hear odd noises like banging, clanking, or gurgling when you try to run water, it could be water trying to force its way past an ice blockage, or the pipe itself contracting.
• Toilet Bowls Not Refilling / Appliances Malfunctioning: If your toilet bowl isn’t refilling after a flush, or appliances like your dishwasher or washing machine aren’t getting water, it points to a frozen supply line.
• Damp Drywall or Ceilings / Sudden Drop in Water Pressure: These are more severe signs, often indicating that a pipe has already burst. If you notice damp spots, water stains, or a sudden, unexplained drop in your home’s overall water pressure, it’s crucial to act immediately.

For a comprehensive guide on what to do if you suspect a burst pipe, we encourage you to review What to Do When Your Pipes Burst: A Step-by-Step Guide for Chicago Homeowners.

The Science Behind a Burst Pipe

It’s a common misconception that the ice itself breaks the pipe. The actual cause is immense pressure. Water expands by about 9% when it freezes. Inside a pipe, this expansion creates an ice blockage that acts like a piston, pushing unfrozen water forward.

If the faucet is closed, the pressure between the ice and the faucet can skyrocket to over 2,000 pounds per square inch (PSI)—far beyond the typical 40-80 PSI of household water pressure. This incredible force is what ruptures the pipe, often at a weak point away from the actual ice block. The result can be a catastrophic rupture, leading to severe Storm Damage and extensive water damage.

Are Some Pipes More Likely to Freeze and Burst?

Yes, the pipe material significantly impacts its susceptibility to bursting once frozen. This is a critical consideration for homeowners in our cold climate zones of Illinois, Wisconsin, and Indiana.

Let’s compare some common pipe materials:

Pipe Material	Characteristics	Freezing Risk	Bursting Risk (when frozen)
Copper	Excellent conductor of heat/cold, rigid	High (freezes faster)	High (less flexible)
PEX	Cross-linked polyethylene, very flexible	Moderate	Low (can expand with ice)
PVC	Rigid plastic, common for drains but also supply	Moderate	High (rigid, similar to copper)
Galvanized Steel	Rigid, older material	Moderate	High (rigid)

Copper Pipes: These are common in many homes. As a good thermal conductor, copper transfers cold to the water inside relatively quickly. Its rigid nature means it cannot expand to accommodate the ice, leading to a high likelihood of bursting under pressure.

PEX Pipes: Increasingly popular in modern plumbing, PEX is flexible and can expand to accommodate freezing water. While PEX pipes can still freeze, they are considerably less likely to burst than their metal counterparts.

PVC & Galvanized Steel Pipes: Like copper, these materials are rigid and have limited capacity to expand under the pressure of freezing water. Therefore, they are also at a high risk of bursting once frozen.

Understanding your home’s plumbing materials can help you assess your risk. Regardless of pipe type, prevention is always the best strategy. However, if a burst occurs, swift and professional water damage restoration is essential to mitigate the damage. Learn more about Why Professional Water Restoration is Important.

Step 3: Take Action with Prevention and Thawing Methods

Now that we understand at what temperature do pipes freeze, the factors that influence it, and the signs of trouble, it’s time for action! Proactive prevention is always the best defense against the destructive force of frozen and burst pipes. However, if you find yourself facing a frozen pipe, knowing the safest and most effective thawing methods is crucial.

The importance of immediate action cannot be overstated. A frozen pipe is a ticking time bomb, and every moment counts in preventing a costly burst. Safety first! Never use dangerous methods that could cause further damage or injury.

7 Essential Prevention Tips

Protecting your home’s plumbing in the Chicago winter requires a multi-faceted approach. Here are our top 7 essential prevention tips to keep your pipes from freezing:

1. Insulate Pipes in Vulnerable Areas: This is your first line of defense. Focus on pipes in unheated spaces like basements, attics, crawl spaces, and garages, as well as pipes running along exterior walls. You can use foam pipe sleeves (often resembling pool noodles), fiberglass insulation, or electric heating tape/cable. According to Energy Saver, the best pipe insulation can raise your water temperature by 3 to 4 degrees, significantly delaying freezing.
2. Seal Air Leaks and Cracks: Cold air is a pipe’s worst enemy. Inspect your home for any gaps, cracks, or openings in exterior walls, foundations, and around utility penetrations (where pipes, wires, or dryer vents enter the house). Use caulk or weatherstripping to seal these openings, preventing cold drafts from reaching your plumbing.
3. Let Faucets Drip During Extreme Cold: A slow, steady drip from a faucet, especially one on an exterior wall, can prevent freezing. The moving water, even a trickle, makes it harder for ice to form a solid blockage, and it relieves pressure buildup if a blockage does occur further down the line. It doesn’t need to be a stream, just a consistent drip.
4. Open Cabinet Doors Under Sinks: For pipes located in cabinets against exterior walls in kitchens or bathrooms, open the cabinet doors during severe cold snaps. This allows warmer air from the room to circulate around the pipes, providing much-needed heat.
5. Maintain a Consistent Thermostat Setting (55°F+): Even if you’re leaving town for a few days, keep your home’s thermostat set to at least 55°F (13°C). This ensures that enough ambient heat reaches pipes throughout your home, even in less-used areas. Turning off your heat entirely is a recipe for disaster in our climate.
6. Winterize Outdoor Faucets and Sprinkler Systems: Before winter officially sets in, drain your outdoor hose bibs and irrigation systems. Disconnect all garden hoses from outdoor spigots, drain them, and store them indoors. Then, close the interior shut-off valves that supply your outdoor faucets and open the outdoor spigots to allow any remaining water to drain out and relieve pressure. Consider installing frost-free spigots for added protection.
7. Insulate and Cover Crawl Spaces: If you have a crawl space, ensure it is properly insulated and that any vents are closed or covered during winter. This prevents cold air from circulating freely around pipes in this vulnerable area.

Proper insulation is a game-changer. For more details on effective pipe insulation, refer to this resource from The best pipe insulation.

Safe Ways to Thaw a Frozen Pipe

If, despite your best efforts, you suspect a pipe has frozen, act quickly and safely. Here’s what we recommend:

1. Turn Off the Main Water Supply: This is the most crucial first step. If the pipe bursts while you’re thawing it, or if it has already burst, shutting off the water main will prevent widespread flooding and catastrophic water damage to your home.
2. Open the Frozen Faucet: Locate the faucet that the frozen pipe supplies and open it. Even if no water comes out, leave it open. This allows water to start flowing as the ice melts and helps to relieve pressure buildup behind the ice blockage.
3. Apply Gentle, Even Heat to the Frozen Section:
   • Hair Dryer Method: This is one of the safest and most effective methods. Use a standard hair dryer on a low or medium setting. Start applying heat near the faucet end of the frozen section and work your way back towards the main water supply, gradually melting the ice.
   • Electric Heating Pad: Wrap an electric heating pad around the frozen section of the pipe. This provides consistent, gentle heat.
   • Hot Towels: Soak towels in hot water and wrap them around the frozen pipe. Replace them frequently as they cool.
   • Portable Space Heater: You can use a small portable space heater to warm the general area around the frozen pipe, but always keep it several feet away from flammable materials and never leave it unattended.
   • Continue until water flow returns: Keep applying heat until water begins to flow freely from the open faucet. Even after flow returns, keep the faucet dripping slightly to prevent refreezing.

What NOT to Do: Never, ever use an open flame device like a blowtorch, propane heater, kerosene heater, or charcoal stove to thaw a frozen pipe. This is an extreme fire hazard and can severely damage your pipes, potentially causing them to burst or melt. Do not use boiling water directly on pipes, as rapid temperature changes can crack or damage them.

Calling a Professional: If the frozen pipe is inaccessible (e.g., behind a wall or under a concrete slab), if you can’t locate the frozen section, or if you’re unable to thaw it yourself, it’s time to call a licensed plumber. If you find a burst pipe and water is flowing, call us immediately at Chicago Water & Fire Restoration. We specialize in handling Flooded Basement emergencies and other water damage scenarios.

Frequently Asked Questions about Frozen Pipes

We get a lot of questions about frozen pipes, especially during our harsh Chicago winters. Here are some of the most common ones, answered directly to help you stay informed and prepared.

Do frozen pipes always burst?

No, frozen pipes do not always burst, but the risk is very high, and it increases significantly the longer they remain frozen and the colder the temperatures get. The key factor is the pressure created by expanding ice. If there’s enough space for the ice to expand, or if the pipe material is flexible enough to accommodate the expansion (like PEX pipes), a burst might be avoided.

However, rigid pipes like copper, galvanized steel, or PVC have very little give. Once the internal pressure from the expanding ice exceeds the pipe’s structural integrity, it will rupture. That’s why prompt detection and safe thawing are so crucial. Our goal is always to thaw a frozen pipe before it bursts, saving you from a much larger and more expensive problem.

Can pipes freeze in one night?

Absolutely, yes. Depending on the outdoor temperature, the pipe’s location, and its insulation, pipes can freeze in a single night. In temperatures of 20°F (-6°C) or colder, especially with wind chill, uninsulated pipes can freeze in as little as two hours. Even insulated pipes can freeze in under six hours in such extreme conditions.

For temperatures between 20°F and 32°F, it might take a bit longer—around 6 to 8 hours for uninsulated pipes, or up to 12 hours. Given that our winter nights in Chicago, Illinois, Wisconsin, and Indiana often drop well below 20°F for extended periods, it’s entirely possible for pipes to freeze solid overnight. This underscores why proactive prevention is so vital.

What should I do if a pipe bursts?

If you find a burst pipe, it’s an emergency that requires immediate action to minimize damage. Here are the steps you should take:

1. Immediately Shut Off the Main Water Valve: This is the most critical step. Knowing the location of your main water shut-off valve is essential for every homeowner. Turning it off will stop the flow of water and prevent further flooding.
2. Call a Professional Restoration Service: Once the water is off, contact a reputable water damage restoration company like Chicago Water & Fire Restoration. We are equipped to handle the rapid extraction of water, thorough drying, and complete restoration of your property.
3. Document the Damage: Before any cleanup begins, take extensive photos and videos of the damaged area, including the burst pipe itself, any saturated materials, and affected belongings. This documentation will be invaluable for your insurance claim.
4. Remove Excess Water Safely: If it’s safe to do so, you can begin removing standing water using buckets, mops, or wet/dry vacuums. Be cautious of electrical hazards.
5. Contact Your Insurance Company: Notify your insurance provider about the burst pipe and the resulting water damage. We can assist you with the claims process, as we offer direct insurance billing with no upfront costs. Learn more about What Chicago Property Owners Should Know About Insurance, City Codes, & Restoration Requirements.

Protect Your Chicago Home from Winter Water Damage

Understanding at what temperature do pipes freeze is more than just a piece of trivia; it’s a fundamental aspect of winter home maintenance, especially for properties in the Chicago metropolitan area, Illinois, Wisconsin, and Indiana. By following our three easy-to-follow steps – understanding the temperature risks, recognizing the signs of frozen or burst pipes, and implementing effective prevention and thawing methods – you can significantly reduce your risk of a plumbing disaster.

The cost of inaction can be staggering. A burst pipe can release hundreds of gallons of water, leading to extensive structural damage, ruined possessions, and the potential for mold growth. The financial and emotional toll can be immense. But with proper preparation, you can enjoy a worry-free winter, knowing your home’s plumbing is protected.

If, despite your best efforts, winter gets the better of your pipes and you experience a burst, we at Chicago Water & Fire Restoration are here to help. We offer 24/7 emergency water damage restoration services, providing a turnkey solution from mitigation to repairs, backed by 25+ years of IICRC-certified expertise and a 2-year warranty. Don’t let a burst pipe turn your home into an ice rink.

For immediate assistance or professional water damage restoration, please don’t hesitate to Contact us for professional water damage restoration. We’re always ready to restore your peace of mind.