Which Pipes Are Actually at Risk
Not every pipe in your home faces the same freeze risk, and knowing which ones do lets you focus prevention effort where it matters.
Highest-Risk Locations
Pipes running along exterior walls, especially in older Arlington homes built before modern insulation standards, are exposed to outdoor temperature swings the rest of the house doesn't feel. Unheated or under-insulated crawlspaces — common under many of Arlington's older single-family homes — leave supply lines directly exposed to whatever the outside air is doing. Garages, particularly detached ones, and any pipe run through an unheated addition or sunporch carry similar risk.
Hose Bibs and Their Interior Shutoffs
Exterior faucets are often the very first thing to freeze, and if the interior shutoff valve feeding them isn't also closed and drained, the freeze can travel back into the wall and crack the supply line behind it — a much more expensive repair than a cracked hose bib alone.
Before the Cold Hits: Your Fall Checklist
Disconnect and Drain Garden Hoses
A hose left attached over winter traps water in the bib and defeats even a frost-free design's protection — disconnect and drain every hose before the first hard freeze, typically by late October in this area.
Insulate Exposed Pipe Runs
Foam pipe insulation sleeves are inexpensive and simple to install on any accessible exposed pipe in a crawlspace, garage, or basement — this single step prevents a meaningful share of the frozen pipe calls we run every winter.
Seal Air Leaks Near Pipes
Gaps around where pipes enter the house from outside, or drafts near foundation vents, let cold air reach pipes that would otherwise stay above freezing — sealing these is often overlooked but genuinely effective.
Know Where Your Main Shut-Off Is
If a pipe does freeze and crack, being able to shut off water immediately prevents a frozen pipe from becoming a flooded basement the moment it thaws.
During a Hard Freeze
Let Faucets Drip on Exterior Walls
A slow, steady drip keeps water moving through the pipe, which meaningfully reduces freezing risk during the coldest overnight hours — the minor water cost is far cheaper than a burst pipe.
Open Cabinet Doors
Cabinets under sinks on exterior walls trap cold air around the pipes; opening them during a hard freeze lets warmer room air circulate around the plumbing.
Keep the Heat On, Even If You're Away
Setting the thermostat no lower than 55°F, even during a trip, keeps interior temperatures high enough to protect pipes that a fully unheated house would put at serious risk.
If a Pipe Has Already Frozen
Catching a frozen (but not yet burst) pipe early can prevent it from cracking at all.
Shut Off the Main Water Supply First
Before attempting to thaw anything, shut off your main valve. If the pipe has already cracked from the freeze, thawing it without the water off means an immediate flood the moment ice gives way.
Locate and Warm the Frozen Section
Open the faucet the frozen section feeds, then warm the pipe gradually using a hair dryer, a space heater kept a safe distance away, or towels soaked in hot water — never an open flame, which is a fire risk and can damage the pipe further.
When to Call Rather Than Continue DIY
If you can't locate the frozen section, if water still isn't returning after a reasonable thawing effort, or if you notice any sign of a crack (dampness, bulging), stop and call a plumber before proceeding further — a pipe that's already compromised can fail suddenly once it fully thaws.
Arlington-Specific Risk Factors
Homes in Cherrydale, Westover, and other established North Arlington neighborhoods, many built in the 1930s-1950s, are statistically more likely to have uninsulated crawlspaces and original pipe runs that predate modern freeze-prevention standards. If your home falls into this category and you've never had exposed pipes assessed, a preventive check before winter is a reasonable investment relative to the cost of even one frozen-pipe emergency call.
Need a Plumber in Arlington?
Licensed, upfront, and available 24/7. Call (571) 202-6461 or request a free quote.
Frequently Asked Questions
What temperature actually causes pipes to freeze?
Risk rises sharply once temperatures stay below 20°F for several sustained hours, especially in unheated or under-insulated spaces.
Should I leave cabinet doors open every night in winter, or just during a hard freeze?
Just during genuinely cold snaps — it's not necessary on an average winter night, only when temperatures are forecast to stay well below freezing.
How much does it cost to insulate exposed pipes proactively?
Foam pipe insulation sleeves are inexpensive, and for most homes the material cost for a full crawlspace is a small fraction of what one frozen-pipe emergency call typically costs.
Can a frozen pipe thaw on its own without bursting?
Sometimes, if it wasn't under much pressure buildup — but there's no reliable way to know that in advance, which is why shutting off the water before it thaws is the safer approach.
Do frost-free hose bibs eliminate freeze risk entirely?
They significantly reduce it by moving the shutoff point further back into the heated wall, but they're not foolproof if a hose is left attached, which defeats the design.
Is it worth having a plumber inspect my crawlspace before winter?
For older homes with a history of freeze issues, yes — it's a relatively low-cost way to catch vulnerable pipe runs before the season's first hard freeze.