How to Stop Frozen Pipes Before Winter Hits Long Island

Every winter I get the same call in January, usually the week after a hard cold snap, and it's always the same sentence: "we heard dripping and then nothing and then water on the ceiling." By the time a pipe bursts, you're not looking at a repair anymore, you're looking at cut drywall, a wet subfloor, and a claim. The pipe itself takes ten minutes to fix. The water it put out over six hours before anyone noticed is the real job.

Long Island doesn't get Minnesota cold, and that's exactly the problem. We run through 40 to 50 freeze-thaw cycles in a normal season, nights in the teens followed by a 40-degree afternoon, over and over. Pipes that would stay frozen solid and intact in a consistently cold climate here freeze, expand, thaw, refreeze, and expand again. That cycling is what cracks copper and splits PEX fittings, not one cold night.

The other piece is wind. A nor'easter coming off the Atlantic or the Sound doesn't just drop the temperature, it drives wind straight into rim joists, vented crawlspace blocks, and garage header gaps that never mattered until the gusts hit 40 miles an hour. A pipe sitting two feet from one of those gaps can freeze on a night when your thermostat reads 68.

Where Pipes Actually Freeze on Long Island Homes

It's never the pipes in the middle of the house. In twenty-plus years of doing this work from Huntington to Southampton, the failures cluster in the same four spots every time: crawlspaces, garages built over living space, exterior walls on the north and east sides, and hose bibs that never got shut off at the interior valve. If you only have budget to address one thing this fall, walk those four locations first.

Crawlspaces: The Number One Culprit

South Shore homes in Babylon, Islip, and parts of Bay Shore sit on sandy soil with a high water table, which means a lot of crawlspaces are damp even when they're not actively flooding. Damp ground under a vented crawlspace means the air down there tracks close to outdoor temperature all winter. Any supply line running through that space without insulation is exposed. I've pulled apart plenty of crawlspace pipe wrap that was installed a decade ago, sagging, gapped at every joint, doing almost nothing. If your crawlspace is still vented, insulate the pipes and consider closing the vents for winter. If moisture is a recurring issue down there, that's a separate problem worth solving before you finish anything above it. Our basement waterproofing guide covers how we handle that kind of ground moisture on Long Island lots.

Garages Over Living Space

This is the one homeowners never expect. A garage built under a bedroom or laundry room often has supply lines running through the garage ceiling, and that ceiling is almost never insulated to the same standard as the rest of the house because nobody thinks of a garage as part of the thermal envelope. Leave the garage door open for twenty minutes on a 20-degree day loading groceries, and you've just dropped the temperature around that pipe run by 30 degrees. If you've got a washer hookup or a half-bath above or adjacent to the garage, check it specifically. That's where I see the most garage-related bursts.

Exterior Walls and Hose Bibs

Kitchen sinks and bathrooms on exterior walls, especially additions built without full wall cavity depth, put supply lines within an inch or two of siding with nothing but a stud bay between the pipe and 20-degree air. Salt air off three sides of this Island accelerates the breakdown of old caulk and flashing around penetrations, which lets more cold air track into those cavities than the original builder accounted for. Hose bibs are the easy one everyone forgets: if you don't have frost-free sillcocks, shut the interior valve and drain the line before the first hard freeze, every single year. A hose bib that stays charged with water through a nor'easter is one of the most common single-point failures I see, and it's the cheapest one to prevent.

Heat Cable vs. Insulation vs. Rerouting

These are three different tools for three different problems, and homeowners often reach for the wrong one. Pipe insulation (foam sleeves or wrap) slows heat loss and buys you time during a cold snap, but it doesn't generate heat, so it won't save a pipe in a space with zero ambient warmth at all. Heat cable, installed correctly with a thermostat control, actually adds heat to the pipe and is the right call for a known cold spot like an exposed crawlspace run or a line in an unheated garage ceiling. The failure mode with heat cable is almost always installation: cable that's not rated for the application, wrapped under insulation instead of against the pipe per the manufacturer's spec, or plugged into an outlet on a circuit that trips and nobody notices until February. Rerouting is the permanent fix, moving the line out of the exterior wall or unheated space entirely during a renovation, and it's worth doing anytime you've already got a wall open for other work rather than patching the same cold spot every year.

What to Do in the First 10 Minutes If a Pipe Bursts

Shut off the main water valve first, before you do anything else, including before you start mopping. Most Long Island homes have the main near the water meter in the basement or a utility closet, know where yours is before you need it in the dark at 6 a.m. Next, open the nearest faucet on that line to relieve pressure and drain what's left in the pipe. Then kill power to any outlets or fixtures near standing water at the breaker, not by reaching into wet space. Start documenting with your phone before you touch anything you don't have to touch, insurance adjusters want to see the damage as it happened, not after it's been cleaned up. If the water has been running for more than a few minutes, assume it's gotten into wall cavities or subfloor even if the surface looks dry, and get it assessed rather than just drying the visible area. This is exactly the kind of job our insurance restoration team handles start to finish, from the emergency mitigation through the drywall and flooring repair.

Permits and What Your Town Actually Requires

Real pipe rerouting or heat cable tied into new wiring can cross into work that your town's building department wants eyes on, and that varies by municipality. Brookhaven, Islip, Smithtown, Huntington, and the Nassau towns each handle plumbing and electrical permitting a little differently, and homeowner-only permit rules change. Don't assume, call your specific town's building department before work starts, or let your contractor pull the permit as part of the job.

What We Do

We walk the house, find the actual cold-spot pipes instead of guessing, and fix the ones that are one bad night from bursting, whether that means insulation, properly installed heat cable, or rerouting a line while a wall's already open for other work.

Call (631) 312-7441 or book a free walkthrough.

Frequently Asked Questions

How cold does it actually need to get for a Long Island pipe to freeze?

It's less about one cold number and more about sustained exposure. A pipe in an unheated crawlspace or exterior wall can freeze with several hours below freezing, especially with wind driving into the space. Our freeze-thaw cycling, not a single arctic night, is what does the real damage over a season.

Is pipe insulation enough, or do I need heat cable?

Insulation slows heat loss but doesn't add heat, so it works for mild exposure and short cold snaps. A genuinely cold, unheated space like an exposed crawlspace run or a garage ceiling usually needs heat cable with a thermostat control, since insulation alone won't hold a pipe above freezing all night.

Should I leave a faucet dripping during a cold snap?

A slow drip on an exposed line can relieve pressure and reduce burst risk, but it's a stopgap, not a fix. If you're relying on a dripping faucet every winter, the pipe is in a cold spot that needs insulation, heat cable, or rerouting.

My garage is under a bedroom, is that a real risk?

Yes, it's one of the most common freeze locations we see. Supply lines running through an uninsulated garage ceiling lose heat fast, especially if the garage door gets left open for any stretch of time in cold weather. Check that ceiling before winter, it's an easy miss.

What should I do with outdoor hose bibs before winter?

Disconnect and drain your hoses, then shut off the interior valve feeding the hose bib if you have one, and open the outdoor spigot to drain the line. If you don't have frost-free sillcocks and don't know whether there's an interior shutoff, have a plumber check before the first hard freeze.

Do I need a permit to add heat cable or reroute a pipe?

It depends on the scope and your town. Simple plug-in heat cable on an existing circuit usually doesn't trigger a permit, but rerouting plumbing or adding new circuits can. Confirm with your specific town's building department, since Suffolk and Nassau towns handle this differently.

Related Guides

• Basement Waterproofing Before You Finish It
• Finishing a Basement in Winter
• Attic Insulation on Long Island
• Insurance Restoration Services