Why Pipes Burst: Causes, Warning Signs & Prevention

While plumbing pipes are durable and reliable, they’re not invulnerable. Under the wrong circumstances, pipes burst, with potentially catastrophic results. Knowing what causes pipes to burst helps protect your property from costly damage. Join us as we explain why pipes burst, how to respond to a burst water pipe, and what to do to prevent burst pipes. 

What Causes Pipes to Burst?

Freezing temperatures, water pressure, corrosion, and “water hammer” can all cause burst pipes. Here’s a more detailed explanation of what causes pipes to burst:

• Extreme Cold: Cold weather can damage water supply pipes. When water freezes, it expands, increasing the pressure inside the pipe. The increased pressure can cause a water pipe to burst, usually at a weak pipe joint but sometimes right through the pipe wall. Uninsulated pipes in unheated locations such as basements, garages, and crawl spaces are especially vulnerable to freezing. 
• Water Hammer: Poorly installed or unsecured water pipes can move when water is turned on or off. If you’ve ever heard pipes clanging inside walls or floors, it’s called a water hammer. The pipes move back and forth, gradually weakening the joints until one fails, allowing pressurized water to escape. 
• High Water Pressure: A significant increase in water pressure can lead to burst pipes. The water pressure in most homes ranges from 30 to 50 psi and should not exceed 60 psi to avoid damage to pipes and plumbing fixtures. 
• Corrosion: Plumbing pipes provide decades of reliable service but don't last forever. Years of slow-building corrosion can cause a pipe to fail. Hard water minerals may accumulate in older galvanized iron pipes, slowly wearing down the galvanized coating (which itself increases the risk of dangerous lead poisoning) and exposing the iron pipe beneath. Over time, the iron turns to rust (iron oxide), narrowing the pipe diameter so water can barely flow. When this happens, pipes can burst or clog.

At What Temperature Do Pipes Burst?

Water freezes at 32°F (0°C). The longer uninsulated pipes are exposed to cold temperatures, the higher the risk of a pipe burst. At 32°F, pipes can freeze within 12 hours. The lower the temperature drops, the faster pipes freeze: At 0°F, an uninsulated pipe can freeze within three hours. 

Do frozen pipes always burst? Not at all, but each freeze puts pressure on the pipe wall, weakening the wall and increasing the risk of a future burst. Ideally, you’ve already insulated your pipes, but if not, here’s how to unfreeze a frozen pipe. 

How To Know If Your Pipes Burst

Water dripping or pouring out of a pipe is an obvious indication that you have a plumbing problem. Much of a home’s plumbing is hidden behind walls, making it challenging to detect burst pipes, especially if the pipe loses water at a slow rate. Below are some clues that suggest you may have a pipe burst on your property.

Warning Signs of a Water Pipe Burst

• Faucets that sputter and splatter water when opened indicate fluctuating water pressure, which can be the result of a burst pipe somewhere along the supply line. 
• Puddles under sinks.
• Dripping, gurgling, or other strange noises inside walls may originate from burst pipes. 
• Rusty odors due to iron corrosion. 
• Rotten egg smells indicate a broken sewer line. Call Roto-Rooter immediately, as this is a serious plumbing emergency.
• Discolored, stained walls or ceilings. Ceilings may bulge due to water accumulation.
• Mold or mildew growth.
• Bubbling paint or peeling wallpaper. 
• Dripping ceiling fixtures. If you see water dripping from a light fixture, turn off the electricity to the room at your breaker box and call a licensed electrician immediately. 
• Unexplained increases in humidity, especially in attics, bathrooms, laundry rooms, and basements. 
• Pooling water in yards indicates that a drainage pipe or water supply line has burst. 
• Unexplained increase in water bills.

What To Do Once Your Pipe Bursts

Shut off your main water supply immediately if you suspect you have a burst pipe. If water impacts your electrical system, turn off the breaker to the affected area and call an electrician. If it’s safe to do so, you can begin cleaning up the water. 

Call Roto-Rooter's 24/7 emergency hotline. We’ll assess the damage and make all necessary repairs. Our plumbing technicians can also assist you in communicating with your insurance company. For large-scale damage, we offer water damage cleanup and mold remediation services. 

Contact your insurance company and document all property damage. Pictures and videos of the damage help insurance companies process your claim more efficiently. Be sure to keep any receipts for repair expenses. 

How to Prevent Pipes from Bursting

Insulation sleeves and foam insulation are your best defense against frozen pipes. If possible, keep indoor areas with uninsulated pipes at a temperature above freezing.  You can further reduce your risk by opening faucets connected to those pipes and letting them drip. Even a slow drip encourages water flow, reducing the risk of freezing. 

If you have an old plumbing system, consider having Roto-Rooter assess its health. We’ll suggest ways to upgrade your plumbing and lower your risk of burst pipes. 

A burst pipe can be a major disaster and one you want to avoid. With some preventive care — and a little help from the professionals at Roto-Rooter — you can lower your risk of an unpleasant, watery surprise.