Winter has a way of turning everyday home routines into a bit of a high-stakes game—especially when temperatures drop fast and stay there. One of the most stressful (and surprisingly common) cold-weather emergencies is a frozen pipe. It starts quietly: a weak trickle from a faucet, a toilet that won’t refill, a strange smell from a drain. Then it can escalate into the thing everyone dreads: a burst pipe and water everywhere.
If you live in or around St. John’s, you already know that winter weather can be unpredictable and intense. Wind, ice, and sudden freezes can push your plumbing past its comfort zone. The good news is that most frozen pipe problems are preventable with a few smart habits and some targeted upgrades. And if a pipe does freeze, there’s a safe, step-by-step way to handle it without making the situation worse.
This guide walks you through prevention strategies that actually work, how to spot early warning signs, and what to do if you’re already dealing with frozen plumbing. Along the way, we’ll also touch on when it’s time to call in help—because sometimes the fastest fix is bringing in the right pros before a small issue becomes a major repair.
Why pipes freeze in the first place (and why it happens even in “mild” winters)
It’s not just the temperature—it’s where your pipes live
Pipes freeze when the water inside them drops to 0°C and turns to ice. But the outdoor temperature doesn’t need to be brutally cold for that to happen. If a pipe runs through an unheated space—like an attic, crawlspace, garage, exterior wall cavity, or a poorly insulated basement corner—it can freeze even when the rest of your home feels comfortable.
In many homes, the most vulnerable pipes are the ones you rarely think about: the line feeding an outdoor hose bib, the pipe behind a kitchen cabinet on an exterior wall, or plumbing tucked near a rim joist where cold air sneaks in. Add wind chill and drafts, and those areas can dip below freezing quickly.
Another factor is how long the cold lasts. A short overnight dip may not be enough to freeze a well-insulated pipe, but several days of below-freezing weather can slowly pull heat out of the system until ice forms.
Frozen pipes burst because ice blocks pressure—not because ice “expands” inside the whole line
You’ve probably heard that pipes burst because water expands when it freezes. That’s true, but the bigger problem is what happens after an ice plug forms. Once a section freezes, water pressure builds up between the blockage and the nearest closed faucet or valve. That pressure has to go somewhere, and it often finds the weakest point—splitting copper, cracking PEX fittings, or popping joints apart.
What makes this tricky is that the pipe can burst in a different spot than where it froze. You might thaw a line under the sink, only to discover a leak in the wall or ceiling nearby once everything warms up.
That’s why prevention is so valuable: avoiding the freeze prevents the hidden pressure buildup that causes the real damage.
Spotting the early signs before things get expensive
Small changes in flow are your first clue
A frozen pipe doesn’t always announce itself dramatically. Often, the first sign is reduced water pressure at a single fixture. If one faucet suddenly runs at a trickle while others are fine, that localized problem can point to a pipe that’s starting to freeze (or already partially frozen) on that branch line.
Pay attention to patterns. If the kitchen sink slows down only during cold nights and improves during warmer afternoons, you’re likely dealing with a pipe in an exterior wall or a cabinet area that’s too cold.
Another subtle sign is a toilet that refills slowly or not at all. Toilet supply lines can freeze, and because they’re smaller, they can ice up faster than main lines.
Frost, weird smells, and “silent” fixtures
If you can see exposed piping, look for frost or condensation that seems out of place. Frost on a pipe in a basement or crawlspace is a strong warning that conditions are right for freezing.
Sometimes you’ll notice an odd smell coming from a drain. When a pipe freezes, it can block normal venting and drainage, which may allow sewer gases to move in unexpected ways. It’s not always a freeze, but it’s worth investigating—especially during cold snaps.
And of course, the biggest clue: a faucet that won’t run at all. If you turn it on and nothing comes out, treat it as urgent. The longer the pipe stays frozen, the higher the risk of a burst when thawing begins.
Prevention that works: making your plumbing winter-ready
Insulate the right places (not just “more insulation” everywhere)
Insulation is one of the best defenses, but it’s most effective when it’s targeted. Focus on pipes in unheated areas and near exterior walls. Foam pipe sleeves are affordable and easy to install, and they make a meaningful difference for exposed runs in basements, crawlspaces, garages, and utility rooms.
Don’t forget the “transition zones”—where pipes pass through foundation walls, rim joists, or floor cavities. These are prime spots for cold air infiltration. Sealing gaps with appropriate materials (like spray foam around penetrations) can reduce drafts that chill pipes even if the pipe itself is insulated.
If you have pipes in an attic (common in some layouts), insulation alone may not be enough. Attics can get extremely cold, and wind can push frigid air through soffits and vents. In that case, consider rerouting or adding heat where practical.
Heat tape and pipe heating cables: when and how to use them safely
Heat tape (or heating cables) can be a lifesaver for stubborn cold spots. They’re designed to provide gentle warmth along a pipe run, reducing the chance of freezing. But they need to be installed carefully and according to the manufacturer’s instructions—improper use can be a fire risk.
Look for products that are CSA/UL certified, ideally with built-in thermostats that activate only when temperatures drop. Avoid overlapping heat tape unless the product explicitly allows it. Secure it properly, then insulate over it if recommended.
Heat tape is especially useful for pipes that feed outdoor faucets, lines in garages, and plumbing near rim joists. If you’re unsure about installation, it’s worth having a professional handle it—especially in older homes with mixed materials and older wiring.
Keep interior doors open and cabinets vented during deep freezes
This is one of the simplest hacks, and it works surprisingly well. When it’s extremely cold, open cabinet doors under sinks—especially if the plumbing is on an exterior wall. That lets warm household air circulate around the pipes.
Also keep interior doors open to rooms that have plumbing on outside walls or in colder corners of the home. Heat can’t protect what it can’t reach, and closed-off spaces cool down faster than you’d expect.
If you have a basement or utility room that you normally keep cooler, consider bumping the thermostat slightly during cold snaps. The extra cost for a day or two can be far less than the cost and hassle of water damage repairs.
Water habits that reduce freezing risk without wasting a ton
Dripping faucets: when it helps and when it doesn’t
You’ve probably heard the advice to let faucets drip. The idea is that moving water is less likely to freeze and that an open faucet relieves pressure if ice forms. This can help, especially for pipes that are known to freeze, but it’s not a magic fix for every situation.
Dripping is most effective when the vulnerable pipe is close to the faucet you’re dripping and when the water supply line is the one at risk. If the freeze point is far upstream (like a main line in a crawlspace), dripping a faucet might not move enough water through the cold section to prevent freezing.
If you choose to drip, use a steady drip—not a full stream—and focus on the fixtures connected to the pipes that have frozen before or are in the coldest parts of your home.
Know your shutoff valves before you need them
This isn’t exactly a “water habit,” but it’s a winter habit that pays off. Find your main water shutoff valve now, not during a panic. Make sure everyone in the household knows where it is and how to turn it off.
If you have a separate shutoff for outdoor spigots, locate those too. In many homes, there’s an interior valve that controls the exterior faucet. Turning that off and draining the line is one of the best ways to prevent a frozen hose bib.
Also check that the valve actually works. Older valves can seize. If yours is stiff or corroded, get it serviced or replaced before winter hits hard.
Outdoor plumbing and the areas people forget
Hose bibs, outdoor taps, and the “one warm day” trap
Outdoor faucets are frequent freezing culprits because they’re literally connected to the outdoors. The classic mistake is leaving a hose attached. Even if the tap is off, a connected hose can trap water in the faucet and the supply line, making freezing much more likely.
Before winter, disconnect hoses, drain them, and store them. If you have an interior shutoff for the outdoor line, close it and open the outdoor faucet to drain any remaining water. If your home has frost-free hose bibs, they’re more resistant to freezing—but only if they’re installed correctly and the hose is removed.
Another sneaky issue: a warm spell in early winter can make you forget to winterize. Then temperatures drop suddenly, and you’re caught off guard. Treat winterizing like changing smoke detector batteries—do it early, not when you “feel like it.”
Garages, crawlspaces, and under-porch lines
Garages are often unheated or only lightly heated, and they can get colder than you think—especially if the door opens frequently. If you have plumbing in a garage wall, consider adding insulation and keeping the garage door closed as much as possible during cold snaps.
Crawlspaces are another major risk area. Even if the house above is warm, cold air can circulate in a crawlspace and freeze pipes that run under the floor. Insulating crawlspace walls, sealing vents appropriately for your climate, and insulating pipes can all help.
Some homes have plumbing lines running under porches or additions with minimal insulation. These are notorious for freezing. If you’ve had repeated issues, it may be worth rerouting those lines or adding dedicated heat.
If a pipe freezes: a calm, safe game plan
Step one: confirm the freeze and reduce risk
If you suspect a frozen pipe, start by checking other fixtures. If the whole house has no water, the freeze might be on the main line where it enters the home. If only one fixture is affected, the freeze is likely on that branch line.
Turn the affected faucet on slightly. This is important: as you thaw the pipe, melting ice needs a place to go. An open faucet also helps relieve pressure and can reduce the chance of a burst.
If you can access the suspected frozen area, look for bulging, frost, or visible ice. If you see any cracks, splits, or active leaking, shut off the main water supply immediately and skip to the “after thawing” section below.
Thawing methods that are effective (and ones to avoid)
The safest DIY thawing tools are gentle heat sources: a hair dryer, a heating pad, or warm towels wrapped around the pipe. Start thawing near the faucet end and move toward the frozen section. That approach helps water flow out as it melts.
You can also use a portable space heater to warm the room (not pointed directly at one spot too close). If the pipe is behind a cabinet, open the doors and let warm air circulate.
Avoid open flames like propane torches, BBQ lighters, or candles. They can damage pipes, ignite nearby materials, and create a serious fire hazard. Also avoid pouring boiling water directly on pipes—rapid temperature changes can stress materials and fittings.
When it’s time to stop DIY and call a pro
If you can’t find the frozen section, or if it’s inside a wall, ceiling, or under a floor, it’s usually time to call a plumber. Thawing hidden pipes often requires specialized equipment and careful access to avoid causing more damage.
If you have multiple frozen fixtures, that can indicate a bigger problem—like a freeze on the main line or widespread cold infiltration. A pro can assess the whole system and help prevent a repeat.
And if you suspect the pipe may have burst (even if you don’t see water yet), treat it as urgent. Sometimes a pipe cracks but doesn’t leak until it fully thaws. That’s when water damage can suddenly appear in walls, ceilings, and floors.
After the thaw: what to do next so you don’t get surprised by a leak
Check for damage slowly and methodically
Once water starts flowing again, keep the faucet open and watch for changes in pressure and clarity. Then inspect any accessible piping for drips, moisture, or staining. Use a flashlight and check joints and fittings carefully.
If you had to shut off the main water, turn it back on slowly. A sudden surge in pressure can worsen small cracks. If your home has a pressure-reducing valve, make sure it’s working properly.
Pay attention over the next 24–48 hours. Water can travel along framing and show up far from the actual leak. If you notice damp drywall, bubbling paint, or a musty smell, investigate immediately.
Drying and cleanup: why speed matters
If a pipe burst or even leaked for a short time, quick drying is critical. Water can soak into insulation, subfloors, and wall cavities—areas that don’t dry well on their own. The longer moisture sits, the higher the risk of swelling, warping, and microbial growth.
In many cases, the right move is to bring in a team that can handle extraction, drying, dehumidification, and moisture monitoring. That’s the difference between “we cleaned it up” and “we actually prevented hidden damage.” If you need professional help in the Avalon region, PuroClean Avalon is one option homeowners often look to when winter plumbing problems turn into water damage.
Even if the visible mess seems small, remember that water tends to spread under flooring and behind baseboards. A professional assessment can help you avoid the frustrating scenario where everything looks fine… until the smell shows up weeks later.
How to reduce the chance of mould after a winter water incident
Why mould can follow frozen pipe events
Mould doesn’t need a flood to become a problem. It needs moisture, organic material (like drywall paper, wood, dust), and time. A burst pipe provides all three—especially if water reaches wall cavities or insulation where airflow is limited.
In winter, indoor humidity can be lower, which helps a bit. But hidden wet materials can stay damp for a long time, particularly behind vapor barriers or under layered flooring. That’s why “it feels dry” isn’t always a reliable indicator.
If you notice persistent musty odours, worsening allergies, or staining on walls and ceilings after a leak, it’s worth taking seriously. Mould issues can grow quietly and become much harder to address later.
Signs you should get a professional mould assessment
Some red flags include swelling baseboards, peeling paint, soft drywall, or recurring condensation in the same area. Another clue is if you had water in a room and it wasn’t dried with proper equipment (air movers and dehumidifiers) soon after the incident.
If the leak affected a bathroom, kitchen, or basement area, the risk can be higher due to existing humidity and materials that trap moisture. And if anyone in the home has asthma or sensitivities, it’s smart to be extra cautious.
When mould is suspected, professional remediation is typically safer than DIY scrubbing—especially if the affected area is larger or inside building materials. If you’re in the area and need quick mould restoration in St. John’s, it can help to choose a provider that can identify moisture sources, remove damaged materials safely, and verify drying so the issue doesn’t come right back.
Planning ahead: a practical winter checklist for homeowners and renters
What to do before the first deep freeze
Start with the basics: disconnect hoses, shut off and drain outdoor lines if possible, and insulate exposed pipes in unheated areas. Test your main shutoff valve and make sure it’s accessible (not buried behind storage).
Walk through your home and identify cold zones: rooms over garages, basement corners, under-sink cabinets on exterior walls, and any plumbing near drafty windows or doors. Seal obvious air leaks and consider adding weatherstripping.
If you’re a renter, you can still do a lot: keep cabinet doors open during cold snaps, report drafts or broken seals, and ask your landlord about pipe insulation and outdoor shutoffs. Knowing where the shutoff is matters even if you don’t own the place.
What to do when a cold snap is forecasted
When you see a stretch of very cold nights coming, take a few small steps that can prevent a big headache. Keep your home at a consistent temperature (avoid turning the heat way down overnight), open cabinet doors where needed, and consider a controlled drip on the most vulnerable fixtures.
If you’ll be away, don’t shut the heat off completely. Set the thermostat to a safe minimum (often around 12–15°C, depending on your home and plumbing layout). Ask a neighbour or friend to check in if you’re gone for more than a day.
Also, clear snow and ice away from vents and access points where possible. Some plumbing issues are tied to ventilation and airflow, and blocked vents can create unexpected problems in winter.
When frozen pipes lead to water damage: getting the right help fast
Why “cleanup” and “restoration” aren’t the same thing
After a burst pipe, it’s tempting to grab towels, run a fan, and assume the job is done. For small spills on tile, that might be enough. But when water gets into drywall, insulation, or subflooring, proper restoration usually involves moisture detection, controlled drying, and sometimes selective removal of materials that can’t be dried effectively.
This isn’t about being dramatic—it’s about physics. Hidden moisture can linger and cause odours, staining, warped floors, and mould. A restoration-focused approach aims to prevent those secondary issues, not just make the room look okay today.
If you’re dealing with anything beyond a minor, fully visible spill, consider a complete water remediation service so moisture is handled thoroughly and the risk of future surprises is reduced.
What to document and how to protect your home while you wait
If you’ve had a leak or burst, take photos and videos as soon as it’s safe. Document where the water traveled, any visible damage, and the source if you can identify it. This can help with insurance and with the professionals assessing the scope of work.
While waiting for help, prioritize safety: shut off water, turn off electricity to affected areas if there’s any risk, and remove items from wet floors. If you can, gently blot standing water and improve airflow by opening doors and running fans (without pointing high heat at wet materials).
Try not to seal up wet areas too soon. For example, avoid repainting or patching drywall until you’re sure everything is dry. Covering moisture can trap it inside and create a longer-term problem.
Common myths that make frozen pipe problems worse
Myth: “If my water is running, I’m safe”
It’s possible for a pipe to be partially frozen and still allow some water through. That small flow can lull you into thinking everything is fine, while the ice plug grows and pressure builds elsewhere.
If you notice reduced pressure during cold weather, treat it as a warning sign. Check vulnerable areas, increase warmth around the pipe, and monitor closely.
Also remember that different lines freeze at different rates. The bathroom might be fine while the kitchen line in an exterior wall is freezing up.
Myth: “Turning up the heat for an hour will fix it”
Sometimes it will, but not always—and it can create a false sense of security. If a pipe is frozen inside a wall, the surrounding insulation may keep warm air from reaching it quickly. You might need directed heat (like a hair dryer on the accessible section) or professional thawing tools.
Even if you do get water flowing again, that doesn’t guarantee the pipe is intact. A crack can stay hidden until pressure returns fully or until the pipe warms enough to expand.
The better approach is to thaw carefully, inspect, and keep an eye out for leaks over the next day or two.
Building a long-term “no-freeze” strategy for next winter
Small upgrades that have a big payoff
If you’ve had frozen pipes before, it’s worth investing in a more permanent fix. Adding insulation to rim joists, sealing air leaks, and insulating specific pipe runs often solves repeat problems. In some homes, relocating a pipe a few inches away from an exterior wall can make all the difference.
Consider upgrading vulnerable outdoor faucets to frost-free hose bibs if your home’s setup allows it. Also consider adding shutoff valves where they’re missing—especially for outdoor lines and for branch lines feeding problem areas.
Smart home tools can help too. Leak detectors placed near water heaters, under sinks, and in basements can alert you quickly if a thaw leads to a leak. That early warning can prevent extensive damage.
Make winter prep a routine, not a reaction
The biggest difference between “we always have winter plumbing issues” and “we rarely do” is routine. If you set a reminder each fall to do a quick plumbing walk-through, you’ll catch issues like missing insulation, drafty access panels, and hoses left attached.
It also helps to keep a small winter kit: foam pipe insulation, a hair dryer or heating pad, towels, a flashlight, and the phone number of a plumber or restoration service you trust. When something happens at 10 p.m. during a cold snap, you’ll be glad you planned ahead.
Winter can be tough on homes, but frozen pipes don’t have to be part of the season. With a little preparation—and a clear plan for what to do if things freeze—you can protect your plumbing, your floors and walls, and your peace of mind.