Frozen Pipes in Alpharetta — How to Prep When the Forecast Drops Below 25°F
Alpharetta sees a few hard freeze nights most winters. Here's how to prep your home before the forecast drops below 25°F — and what to do if pipes freeze anyway.
Alpharetta isn't Minneapolis but it isn't Miami either. Most winters see a handful of nights with lows below 25°F, and a few of those drop into the teens. For pipes that aren't ready for freezing weather, those nights are when burst pipes happen — usually announced by water spraying inside a wall the next morning when the ice plug shifts on thaw.
Most burst pipes from freezing are preventable with a few hours of preparation in late fall and some awareness during forecast freeze events. This guide walks through what to do, in priority order.
Why pipes burst when they freeze
Water expands when it freezes — about 9% by volume. In an open container that's not a problem. In a sealed pipe, the expansion has to go somewhere, and the consequence is usually a small split along the pipe wall.
The interesting part is that the split usually doesn't leak immediately. The ice plug itself is what's holding water back. As long as the pipe stays frozen, water doesn't escape. The leak appears when the pipe thaws — the ice plug releases, water pressure resumes, and water sprays through the split.
This is why most burst-pipe damage happens during the warm-up after a freeze rather than during the freeze itself. Homeowners often discover the damage when they wake up to find water coming through a ceiling, even though the temperature outside has been climbing for hours.
Where pipes freeze in Alpharetta homes
Four vulnerable locations, in approximate order of frequency:
1. Crawl space supply lines near foundation vents. Pipes running within a few feet of an open foundation vent are exposed to outdoor air temperature. Most Alpharetta crawl spaces have manually-operated vents that should be closed in winter and open in summer. Vents left open during a freeze event are the #1 cause of crawl space pipe freezing.
2. Exterior hose bibs. Standard hose bibs (not frost-free models) have the shutoff valve at the bib itself. Water sits in the pipe between the bib and the wall, exposed to exterior temperature on the bib side. Freezes and bursts inside the wall cavity — and you don't know it happened until spring when you turn the hose bib back on.
3. Unheated garage supply lines. Garages get cold during freeze events. Any plumbing running through an unheated garage — water heater supply lines in some configurations, washing machine supplies on garage-adjacent walls, irrigation supplies — can freeze.
4. Exterior wall plumbing. Pipes running in exterior walls (especially in 2x4 walls without significant insulation) are exposed to cold from the outside. Older Alpharetta homes with original construction sometimes have this vulnerability; newer construction usually places plumbing in interior walls or insulates exterior runs.
Pre-winter checklist (do this in November)
Close foundation vents. Walk the foundation perimeter, identify every vent, close each one. Most have a small latch or slide mechanism. Make a note of where they are so you can reopen them in spring.
Insulate crawl space pipes within 3 feet of foundation vents. Standard foam pipe insulation is cheap, available at home improvement stores, and slides over standard pipe diameters. Wrap any supply lines running near vents.
Drain and disconnect garden hoses. Water trapped in a hose connected to a hose bib backs up into the pipe behind the bib and can freeze even on frost-free models.
If you have standard (non-frost-free) hose bibs, install interior shutoffs. Most newer construction has a shutoff valve inside the house just behind each exterior hose bib. Find it (usually in a basement, crawl space, or near where the hose bib penetrates the wall). Close the interior shutoff and then open the exterior hose bib to drain the line between them.
Locate your main water shutoff and confirm it works. See our main shutoff guide if you're not sure where yours is. Turn the valve to confirm it actually closes — corroded or stuck valves are a problem you want to find in November, not during a freeze emergency.
Identify your garage's supply line situation. If your water heater is in the garage or supply lines run through the garage, those pipes need attention. Heat tape on vulnerable runs is one option; insulation is another.
During a forecast freeze event
When the forecast shows overnight lows below 25°F:
Open cabinet doors under sinks on exterior walls. Lets house heat reach the supply lines behind the wall.
Let a slow drip run on the coldest-exposed fixture overnight. Moving water doesn't freeze as readily as static water. A pencil-thick stream on a kitchen sink or bathroom faucet is usually enough.
Set the thermostat at 60°F minimum even if no one's home. Many people lower thermostats when away for the weekend. During a freeze event, keep heat on.
If extremely cold and you'll be away (lows in the teens for multiple nights), consider shutting off the main water valve and draining the system. This is reasonable for vacation periods over a hard freeze; it's overkill for normal overnight freeze events.
If pipes freeze anyway — what to do
You wake up to no water from a fixture, or you turn on a fixture and nothing comes out. Probably a frozen line somewhere between the meter and that fixture.
Step 1: Identify the frozen section. Check other fixtures. If only one fixture has no water, the frozen line is probably between that fixture and the main. If multiple fixtures are out, the frozen section is upstream of all of them — typically in the main supply line into the house or in the crawl space.
Step 2: Open the affected fixture. Open the faucet on the frozen line — both hot and cold sides if you're not sure which is frozen. As the ice melts, water will start flowing. Having the fixture open also prevents pressure buildup if the pipe has actually split.
Step 3: Thaw the frozen section. Use a hair dryer or an electric space heater directed at the suspected frozen section. Never use a torch, open flame, or anything with high heat output — house fires from improvised pipe-thawing tools are a recurring winter emergency-call category. Gradual heat is the right approach.
Step 4: Watch carefully as the pipe thaws. If water starts spraying out at any point during thawing, the pipe has split. Close the main water shutoff immediately. Then call us.
If you can't locate the frozen section or can't safely thaw it, call (773) 207-0518. Our emergency dispatch handles freeze events around the clock, and we have equipment for safe thawing of inaccessible frozen pipes.
The burst-pipe scenario specifically
If you discover water actively running where it shouldn't be — through a ceiling, behind a wall, on a floor:
1. Close the main water shutoff immediately. This stops the source. Everything else is recovery.
2. Open a low fixture. Drains trapped water out of the system and reduces pressure on the burst point.
3. Move what you can out of the affected area. Rugs, electronics, furniture. The first hour after a burst is when most of the savable damage gets saved or lost.
4. Call us at (773) 207-0518. Our trucks carry the parts to repair most burst events on the same call.
For water damage cleanup beyond the immediate plumbing repair (wet drywall, soaked carpet, damaged flooring), we work alongside water restoration contractors on larger losses and can recommend partners we've worked with. Fulton County's leak adjustment credit applies to burst-pipe water that hit the meter — we provide documentation needed for that submission.
Long-term prevention
The most cost-effective long-term prevention measures, in order of value:
Replace standard hose bibs with frost-free models on next opportunity. Frost-free hose bibs have the shutoff valve well inside the house, so the freeze-vulnerable pipe section is inside heated space. One-time install, eliminates the burst-hose-bib scenario.
Insulate all crawl space pipes (not just those near vents). Standard foam pipe insulation is cheap; full crawl space coverage takes a few hours but eliminates most crawl space freeze risk.
If your home has chronic freeze problems, consider crawl space encapsulation, which keeps the entire crawl space above freezing year-round. Substantial investment but addresses moisture and pest issues alongside the freeze risk.
Call (773) 207-0518 anytime to discuss specific preparation for your home.
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