Almost every frozen pipe we cut out in Des Plaines and Skokie is in one of four places: an unconditioned crawl space, a pipe run inside an exterior wall, a line crossing an unheated garage or porch roof, or a hose bib that was never a frost-free model. Not one of them freezes because the winter was unusually cold. They freeze because a water line was installed on the cold side of the insulation, and it survived on luck until the first stretch of single digits with wind.
Late September is the right time to deal with this. Everything below is cheap and easy in October and expensive and miserable in January.
Why Pipes Freeze in Our Climate
Water freezes at 32°F, but a pipe rarely fails at 32°F. What fails a pipe is an ice plug forming somewhere along the run while water is trapped between the plug and a closed fixture. The expanding ice has nowhere to go, pressure spikes to thousands of PSI, and the pipe splits — usually not at the ice, but downstream of it at the weakest joint or the thinnest wall.
Three things have to line up for that to happen:
- Cold air reaching the pipe. Almost always an air leak, not a lack of insulation: a rim joist gap, an open crawl space vent, a missing garage door sweep, a hole where a cable or gas line was drilled through.
- No water movement. Pipes that get used regularly rarely freeze. Guest baths, laundry sinks, and second-floor fixtures over unheated garages are the classic victims.
- Time. A pipe in 15°F still air needs a few hours. Add wind through a crawl vent and that drops sharply.
The practical takeaway: stopping the cold air matters more than wrapping the pipe. Insulation around a pipe only slows the loss of heat the pipe already has. If there’s no heat in that space at all, foam sleeves just delay the freeze.
The Four Problem Areas in Des Plaines and Skokie Homes
1. Vented crawl spaces
Plenty of Skokie and Des Plaines homes have additions, sunrooms, or rear kitchens built over a shallow vented crawl. The plumbing for that addition — often the kitchen sink and a half bath — sits in a space that is at outdoor temperature by January. The old advice was to close the vents in the fall and open them in spring, which nobody remembers to do.
The durable fix is to take the crawl out of the outdoors: seal and insulate the rim joist, close the vents permanently, insulate the walls rather than the floor above, and put down a sealed vapor barrier. That’s the same work we describe in our HVAC services for crawl space encapsulation, and it fixes cold floors and musty air at the same time.
2. Pipes in exterior walls
This one is genuinely a plumbing design error, and it’s common in 1950s–70s ranches where the kitchen sink or a bathroom vanity sits on an outside wall. The supply lines were run in the stud bay, on the outside of whatever insulation exists.
Two real fixes: reroute the lines to an interior wall or up from below through conditioned space, or open the wall, move the pipes to the warm side, and re-insulate behind them. Rerouting in PEX is usually cheaper and less invasive than people expect. A do-nothing workaround — leaving the cabinet doors open and a faucet dripping — works, but only as long as somebody is home to do it.
3. Lines over unheated garages and porches
If there’s a bathroom above the garage, its supply lines and often its drain are in the garage ceiling. An uninsulated garage door, a missing bottom sweep, and one 10°F night is all it takes. Insulating and air-sealing the garage ceiling, sealing the door perimeter, and in some cases adding a small amount of conditioned heat to the garage solves it permanently.
4. Hose bibs and irrigation
Standard hose bibs hold water right at the wall. Frost-free sillcocks put the shut-off 6–12 inches inside the heated envelope — but they only work if the hose is disconnected, because a connected hose traps water and defeats the design. Every fall: pull the hoses, drain the irrigation system, and shut the interior stops if your bibs aren’t frost-free.
What It Costs: Prevention vs. Repair
| Work | Typical installed cost (2026, north suburbs) |
|---|---|
| Frost-free hose bib replacement (each) | $275 – $600 |
| Rim joist air sealing + insulation, average basement or crawl | $900 – $2,600 |
| Crawl space vent sealing + wall insulation + vapor barrier | $4,500 – $14,000 |
| Rerouting supply lines out of an exterior wall (one fixture group) | $850 – $2,400 |
| Self-regulating heat cable on an exposed run, with thermostat | $450 – $1,400 |
| Garage ceiling insulation + door sealing | $1,100 – $3,800 |
| Whole-home automatic leak-detection shut-off valve | $850 – $1,900 |
| Thawing and repairing one burst line (no water damage) | $450 – $1,800 |
| Burst line with water damage to finished space | $3,500 – $45,000+ |
Ranges depend on access, pipe material, and how much finished ceiling has to come down. The last two rows are why we push the first seven.
Heat Cable: Useful, But Not a Cure
Self-regulating heat cable is the right answer for a specific case: an exposed run you cannot practically move or bring inside the envelope, like a line crossing a crawl space corner or feeding an outbuilding. Use a UL-listed self-regulating product on a dedicated GFCI-protected circuit, install it under the insulation, and never overlap constant-wattage cable on itself. Most homeowners discover the circuit part the hard way — that’s where our circuits and wiring work comes in on the same visit.
Heat cable is a mitigation, not a design fix. If your response to a frozen pipe is a third heat cable, the pipe is in the wrong place.
Before the First Hard Freeze: A Short Checklist
- Disconnect every hose and drain the irrigation lines.
- Walk the basement and crawl with a flashlight on a windy day. Feel for moving air at the rim joist, around the gas and cable penetrations, and at crawl vents. Seal what you find.
- Check the garage door sweep and the weatherstripping.
- Find your main shut-off, make sure it actually turns, and tell everyone in the house where it is.
- If you leave for more than a couple of days in winter, set the thermostat no lower than 55°F and consider shutting the water off at the main.
- Have the heating system serviced. A furnace that dies at 3 a.m. in January is the single most common cause of house-wide pipe freezing. Our annual maintenance visits catch the failures that cause that.
If a Pipe Is Already Frozen
Open the affected faucet so melt water has somewhere to go, then apply gentle heat — a hair dryer or a space heater aimed at the area, working from the fixture back toward the cold. Never use a torch or open flame: it’s the leading cause of pipe-thaw house fires, and it can crack the pipe from thermal shock. If you can’t find the plug, or the pipe is in a wall, call us. And if water has already escaped, shut the main off first and worry about the pipe second.
Frequently Asked Questions
Does dripping a faucet really help?
Yes, as a short-term measure during a cold snap. Moving water and the relieved pressure both help. It’s a stopgap, not a design solution, and it does nothing for a pipe on a branch you’re not dripping.
Should I insulate the crawl space floor or the crawl space walls?
In our climate, the walls — along with sealing the vents and laying a vapor barrier. Insulating the floor above leaves your plumbing on the cold side, which is the exact problem you’re trying to solve.
Will my insurance cover a burst pipe?
Usually yes for sudden accidental discharge, though many policies exclude damage if the home was unoccupied and unheated. Read your policy’s vacancy language, and note that several carriers give a premium credit for an automatic leak-detection shut-off valve.
My pipes are noisy but never freeze. Same issue?
Different issue — usually water hammer, a loose strap, or high static pressure. Worth checking your pressure regulator, but it’s not a freeze warning sign.
How fast can you get to a frozen or burst pipe?
We prioritize active leaks and no-water calls the same day during cold snaps. Call (847) 221-6280. The honest note: during a region-wide freeze, every plumber in Cook County is booked solid, which is the best argument for doing the prevention work now.
Serving Des Plaines, Skokie, and the Surrounding Suburbs
MMDS does this work across Des Plaines, Skokie, Morton Grove, Niles, Park Ridge, Glenview, and the rest of the north suburbs. See our Des Plaines plumbing and Skokie plumbing pages, or read up on installation and repair services.
Talk to MMDS
MMDS handles HVAC, electrical, and plumbing under one roof across the north and northwest suburbs. Call (847) 221-6280 or request a visit here. Financing is available through Sunbit and PowerPay, so a repair or upgrade can be spread into monthly payments instead of one hit to the bank account.