Introduction
Frozen pipes are a serious concern in NYC during prolonged cold snaps, especially in older buildings where pipes run through uninsulated exterior walls, unheated basements, or near drafty windows. When water freezes inside a pipe, it expands and can crack or burst the pipe — and when it thaws, you are looking at potentially catastrophic water damage to your unit and those below. Prevention is far simpler and cheaper than dealing with the aftermath. A few proactive steps before and during cold weather can protect your home and save thousands in damage.
Step-by-Step Instructions
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Step 1 Identify Vulnerable Pipes
Walk through your apartment and note any water pipes running along exterior walls, near windows, in unheated closets, or under sinks on outside walls. In NYC pre-war buildings, kitchen sinks are often on exterior walls, and the supply pipes behind them are prime candidates for freezing. Check your bathroom as well — pipes in walls facing the building's air shaft or light well are exposed to brutal wind chill. If you can feel cold air near a pipe, that pipe is at risk when temperatures drop below 20°F.
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Step 2 Insulate Exposed Pipes
Wrap all vulnerable pipes with foam pipe insulation sleeves, which are available at any hardware store for about a dollar per six-foot section. The foam tubes have a slit along one side — just open them up and snap them around the pipe. Secure the seams with duct tape or cable ties. For pipes in hard-to-reach areas or with lots of bends, use self-adhesive pipe wrap tape, wrapping in overlapping spirals. Pay extra attention to joints and elbows where the insulation tends to gap. Even this simple step raises the freezing threshold significantly.
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Step 3 Keep Pipes Warm During Cold Snaps
When temperatures are forecast to drop below 20°F, open cabinet doors under kitchen and bathroom sinks to let warm room air circulate around the pipes. If you are leaving your apartment for an extended period during winter, never set the thermostat below 55°F — and in NYC buildings with unreliable heat, consider leaving it even higher. Let faucets on exterior walls drip slowly — even a pencil-thin stream of water prevents freezing because moving water resists ice formation. The small cost of the running water is nothing compared to burst-pipe repairs.
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Step 4 Seal Cold Air Leaks Near Pipes
Check for gaps or cracks in walls where pipes enter your apartment, especially where supply lines come through exterior walls or up from the basement. Seal small gaps with caulk and larger openings with expanding foam insulation. Check under sinks for openings in the wall around the pipes — these are common in NYC apartments and let cold air flow directly onto supply lines. Even stuffing gaps with steel wool (which also helps block pests) and covering with caulk provides meaningful protection against cold air infiltration.
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Step 5 Know What to Do If Pipes Freeze
If you turn on a faucet and only a trickle comes out during cold weather, a pipe is likely frozen. Keep the faucet open so water can flow once it begins to thaw. Apply gentle heat to the suspected frozen section using a hair dryer, heating pad, or towels soaked in hot water. Never use an open flame or a heat gun, as the sudden temperature change can crack the pipe or ignite nearby materials. Work from the faucet end toward the frozen section. If you cannot locate the frozen section or the pipe has already burst, shut off the main water supply immediately and call a plumber.
When to Call a Professional
Call a plumber immediately if a pipe has burst — shut off the main water supply first and call your building super to alert units below. A burst pipe in a NYC apartment can cause tens of thousands of dollars in damage to multiple units and common areas. Also call a pro if you suspect frozen pipes inside walls that you cannot access, or if the frozen section is extensive and not responding to gentle heating. After any pipe freeze, even if it thaws without bursting, have a plumber inspect the pipe — freezing can create hairline cracks that leak slowly and cause hidden water damage over time.
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