The Pipe Freeze Risk Checker scores one pipe from seven answers: the lowest temperature expected, how long the cold lasts, where the pipe runs, its protection, your house heat, drafts and whether it has frozen before. It adds the points, places the total in a Low, Moderate, High or Very high band and lists the specific actions for your answers, such as a trickle or opening cabinet doors.
- The score is a simple sum: temperature 0 to 6, duration 0 to 2, location 0 to 5, protection −2 to +2, house heat 0 to 4, drafts +1 and frozen before +2.
- Bands: 0 to 4 Low, 5 to 8 Moderate, 9 to 12 High, 13 or more Very high.
- The default answers, −15 to −25 °C for two or three days on an unprotected exterior-wall pipe with normal heat, calm air and no history, score 10: High.
- Every result ends with knowing where the main shut-off is; a Very high result adds the frozen-tap instruction: keep the tap open, warm gently from the tap end, never an open flame.
- It is an editorial score, not a prediction: pipes can freeze at any score and survive a high one.
Pipe Freeze Risk Checker
01 /What does the Pipe Freeze Risk Checker do?
It turns a forecast and one pipe's situation into a risk band and a short, specific to-do list. Most frozen-pipe advice is a long generic checklist; this tool asks about one pipe at a time, usually the one you are worried about, and only lists the steps that apply to it. Run it the evening a cold snap is forecast, once for each pipe that concerns you.
It is deliberately simple. Each answer adds a fixed number of points, and the total falls into one of four bands. The weights reflect the patterns described across this site: location and lost heat matter most, protection and drafts shift the odds, and a pipe that froze before is likely to freeze again. The where pipes freeze guide explains the location weights, and the temperature guide explains why duration and drafts count.
02 /How is the score calculated?
The score is the sum of the points for your seven answers. Nothing is multiplied or weighted further.
| Question | Options and points |
|---|---|
| Lowest temperature expected | Above −5 °C: 0 · −5 to −15 °C: 2 · −15 to −25 °C: 4 · Colder than −25 °C: 6 |
| How long the cold lasts | One night: 0 · Two or three days: 1 · A week or more: 2 |
| Where the pipe runs | Heated interior wall: 0 · Exterior wall: 3 · Under a sink on an exterior wall: 3 · Crawlspace or cold basement corner: 4 · Unheated garage: 4 · Cantilevered floor or bay window: 4 · Attic: 5 · Hose bib or outdoor pipe: 5 |
| Protection on the pipe | None: +2 · Foam insulation: 0 · Working heat cable (with insulation): −2 |
| House heat | Normal: 0 · Turned down or away: +1 · Off or power outage: +4 |
| Wind or drafts at the pipe | Calm, sealed: 0 · Windy or drafty: +1 |
| Has it frozen before? | No: 0 · Yes: +2 |
| Score | Band | Badge colour |
|---|---|---|
| 4 or less | Low freeze risk | Green (ok) |
| 5 to 8 | Moderate freeze risk | Amber (caution) |
| 9 to 12 | High freeze risk | Red (avoid) |
| 13 or more | Very high freeze risk | Red (avoid) |
The lowest possible total is −2 (a heated interior wall with working heat cable, above −5 °C for one night) and the highest is 22 (an unprotected attic pipe below −25 °C for a week with the heat off, drafts and a history of freezing). Protection points apply at every location, so an unprotected interior pipe still picks up 2 points; read that as a nudge, not a claim that interior pipes need foam.
03 /Which actions does it recommend, and when?
The action list is built from your answers, in this order. Each line appears only when its condition is met, except the last, which always appears.
| Condition | Action shown |
|---|---|
| Score above 4 | Let a thin, steady trickle run from the tap that pipe feeds during the coldest hours. |
| Location is an exterior wall or under a sink on an exterior wall | Open the cabinet doors so house heat reaches the pipe. |
| Location is a hose bib or outdoor pipe | Disconnect hoses and shut and drain the hose bib from its indoor valve. |
| Location is an unheated garage | Keep the garage door closed; do not rely on a space heater left unattended. |
| No protection, and not a heated interior wall | Insulate the pipe; foam slows freezing but does not stop it in a long cold snap. |
| House heat is turned down, away, off or out | Keep the house heated; if you leave, have someone check it, or shut off and drain the water. |
| The pipe has frozen before | A pipe that has frozen before will again: reroute it, add heat cable, or seal and insulate the cavity. |
| Always | Know where the main shut-off is before you need it. |
A Very high result adds one more paragraph: if a tap has no water in a cold snap, assume the pipe is frozen, keep the tap open, warm it gently from the tap end, never with an open flame, and be ready to shut off the main. The full method is in how to thaw frozen pipes safely.
04 /What do typical results look like?
These worked examples were run through the checker's own arithmetic. The first is the tool's default setting.
| Pipe and forecast | Points | Score and band | Actions listed |
|---|---|---|---|
| Default: exterior wall, −15 to −25 °C, 2 to 3 days, no protection, normal heat, calm, never frozen | 4 + 1 + 3 + 2 + 0 + 0 + 0 | 10, High | Trickle; open cabinet doors; insulate; main shut-off |
| Sink on an exterior wall, −15 to −25 °C, one night, no protection, normal heat, drafty, never frozen | 4 + 0 + 3 + 2 + 0 + 1 + 0 | 10, High | Trickle; open cabinet doors; insulate; main shut-off |
| Hose bib, −5 to −15 °C, one night, no protection, normal heat, calm, never frozen | 2 + 0 + 5 + 2 + 0 + 0 + 0 | 9, High | Trickle; drain the hose bib; insulate; main shut-off |
| Interior wall, −15 to −25 °C, 2 to 3 days, no protection, normal heat, calm, never frozen | 4 + 1 + 0 + 2 + 0 + 0 + 0 | 7, Moderate | Trickle; main shut-off |
| Garage, colder than −25 °C, 2 to 3 days, foam, normal heat, calm, frozen before | 6 + 1 + 4 + 0 + 0 + 0 + 2 | 13, Very high | Trickle; garage door; permanent fix; main shut-off; frozen-tap instruction |
| Cottage crawlspace, colder than −25 °C, a week, foam, heat off, drafty, never frozen | 6 + 2 + 4 + 0 + 4 + 1 + 0 | 17, Very high | Trickle; keep heated or drain; main shut-off; frozen-tap instruction |
| Crawlspace with working heat cable, colder than −25 °C, a week, normal heat, calm, frozen before | 6 + 2 + 4 − 2 + 0 + 0 + 2 | 12, High | Trickle; permanent fix; main shut-off |
Notice what moves a score most. Losing heat adds 4 points at once, as much as the difference between a heated interior wall and a crawlspace. A history of freezing adds 2, the same as having no protection. That mirrors the emphasis in municipal and insurer guidance, which centres on keeping the heat on and protecting known cold spots.
05 /How should I use the result?
- Low (4 or less): no trickle is suggested. Still know where the main shut-off is, and keep the usual habits.
- Moderate (5 to 8): the trickle appears, plus any location-specific step. Do them before the coldest night, not after a tap slows.
- High (9 to 12): do every action listed, and check that pipe or its remote thermometer in the morning.
- Very high (13 or more): do everything listed, stay alert for a tap that stops, and be ready to thaw safely or shut off the main. If the heat is off and cannot be restored, the away and outage guide explains how to drain the plumbing.
Any pipe that scores High or Very high in an ordinary Canadian winter week is a candidate for a permanent fix. Compare the options on the frozen pipe prevention cost page, and see how much time foam buys with the companion How Fast Could This Pipe Freeze? calculator.
06 /What are the checker's limits?
It is an editorial score, as its result says: pipes can freeze at any score, and can survive a high one. The weights are judgement calls based on the patterns in municipal guidance and building science, not a statistical model fitted to claims. It cannot see your wall, the gap at your rim joist, the snow over your service line or how long your furnace will run in a power cut.
- It scores one pipe at a time; the riskiest pipe in the house sets your real risk.
- It does not model buried service lines or meters; those depend on frost depth and are covered in frozen water service lines and meters.
- It treats a trickle as advice, not as an input, so the score does not fall when you start one.
- It assumes the heat cable you select is working; a failed or unplugged cable should be entered as no protection.
Municipal guidance is the better authority on local specifics. Calgary asks residents to keep the thermostat at least 15 °C, Winnipeg no lower than 12 °C at night and when away, and Toronto to keep areas near the water meter warm even when away. Confirm current advice with your own utility.
FAQQuestions people ask
What score means my pipes will freeze?
None does. The checker is an editorial risk score. Higher bands mean more of the conditions that freeze pipes are present, so the actions matter more, but a Low pipe can still freeze and a Very high one can survive.
Why does the checker suggest a trickle only above a score of 4?
Below 5 the conditions are mild enough that a trickle adds little. From Moderate upward, moving water is one of the cheapest and most effective protections for the line feeding that tap.
Does heat cable lower my freeze risk score?
Yes. Working heat cable with insulation subtracts 2 points, foam alone adds nothing, and no protection adds 2. Enter a cable that is unplugged or failed as no protection.
Why does a power outage add so many points?
Losing heat removes the main thing keeping indoor pipes above freezing, so the checker adds 4 points, more than any other single change except the coldest temperature band.
Can I use the checker for a cottage or empty house?
Yes. Choose the pipe's location, set house heat to turned down or off as it applies, and follow the actions. For a long absence, draining the plumbing is usually safer than relying on heat.