What do frozen and burst pipes cost?
Updated August 2026
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Let a pipe freeze and split, and a single burst can spill hundreds of gallons an hour and run $5,000 to $20,000+, which puts it among the most expensive winter insurance claims a homeowner ever files. Pipes let go when the pipe itself drops to about 20F, and the ones in exterior walls, crawl spaces, garages, and attics get there first. The cruel part is the price gap: the habits that stop a freeze cost between nothing and a few dollars a foot, while the cleanup after one costs as much as a used car. This page lays out both sides of that gap, from a $1 foam sleeve to a flooded two-story.
The escalation ladder
Every row below is the same leak, left a little longer. The top is a cheap warning; the bottom is a claim.
| What happens | Typical bill | How fast |
|---|---|---|
| You slip foam sleeves over the exposed pipes | $1–3 per foot, DIY | One afternoon |
| You add thermostatic heat tape to a chronic-freeze run | $25–70 plus a little power | One install |
| You let a faucet drip on a hard-freeze night | $0, pennies of water | Overnight |
| A pipe freezes but you thaw it before it splits | $0–150 if you catch it | Hours |
| A frozen line splits and a plumber repairs it | $500–1,500 per burst | Same day, if you are home |
| A burst runs for hours across two floors | $5,000–20,000+ in water damage | One trip away |
Warning signs
The frozen-pipe window announces itself if you are paying attention. On a bitter morning, a faucet that gives only a trickle or nothing at all is a pipe already frozen somewhere upstream. Run your hand along accessible pipes in the basement and crawl space for frost, condensation, or a section that bulges. A whistling or banging in the walls when you open a tap, and rooms or fixtures on exterior walls that always run coldest, flag the spots at risk. If a faucet suddenly flows again as things warm up, check fast for a leak, because a split pipe often reveals itself only on the thaw.
The prevention math
Nearly every defense against a burst pipe is free or nearly so. On nights forecast below about 20F, let a vulnerable faucet drip, open cabinet doors so heat reaches the pipes, and never let the thermostat drop under 55F, even when you are away. Slip $1–3-per-foot foam sleeves over exposed runs in the garage, crawl space, and rim joist, and disconnect and drain the outdoor hoses in fall. Above all, know where your main shutoff is and that it actually closes, so you can stop a burst in seconds instead of watching it flood. If you are traveling, combine this with shutting off the water before the trip, and for a place that sits empty, step up to full winterizing.
Every line in that table starts with a skipped 10-minute task. OnOtto keeps the 10-minute version on your calendar so the $2,000 version never happens.
Get the nudge before the billFrequently asked questions
At what temperature do pipes actually freeze?
Water inside a pipe starts to freeze once the pipe itself drops to about 20F, not at 32F, because moving water and the surrounding house hold some heat. The danger climbs the longer the cold lasts: roughly 6 or more hours below 20F, especially with wind hitting an uninsulated exterior wall, is the classic burst window. Pipes in unheated garages, crawl spaces, and north walls reach that point first. A sudden cold snap after mild weather catches the most people off guard.
Should I leave a faucet dripping when it is below freezing?
Yes, on the coldest nights. A pencil-lead trickle from the faucet fed by the most vulnerable pipe keeps water moving and relieves the pressure that actually splits a pipe, and it costs only pennies of water. Drip both the hot and cold sides, and pick the faucet farthest from where the line enters the house. Also open the cabinet doors under sinks on exterior walls so household heat reaches the pipes. Drop the habit once temperatures climb back above freezing.
Which pipes freeze first in a house?
The ones with the least heat around them: supply lines in exterior walls, unheated garages, crawl spaces, attics, and along the rim joist, plus the outdoor hose bibb and any pipe in a cabinet against a cold wall. Second homes and additions built over a slab or porch are common trouble spots. Interior pipes in heated space rarely freeze unless the furnace quits. Insulating the exposed runs with $1–3-per-foot foam sleeves is the cheapest place to start.
What do I do the second I find a frozen pipe?
Shut off the main water valve first, because a frozen pipe may already be split and will gush the moment it thaws. Open the affected faucet so melting water and pressure have somewhere to go. Warm the pipe gently with a hair dryer, a space heater, or towels soaked in hot water, working from the faucet back toward the frozen spot. Never use an open flame or a torch. If you cannot reach the pipe or it has burst, call a plumber.