What is worrying you: a freeze is coming

A freeze is coming: what to do today

To prevent frozen pipes in South Carolina, wrap exposed lines, close foundation vents, test your main shutoff and keep faucets flowing¹. The flow has to run the whole time it is below freezing. Cold spells of two days or more, or single digits, are what may freeze pipes under homes².

Start at the crawlspace hatch with a flashlight, the afternoon before the cold arrives.

Updated November 4, 2026, Midlands House Walk

If a pipe has frozen, open the faucets, hot and cold, to help water move¹, and keep open flame away from it. If it has burst, go to the main shutoff, then to water where it shouldn’t be.

Brass tap on a red brick wall with a green hose coiled on pine straw — A brass outdoor tap with a green hose coiled below. Unhook yours before the cold comes, because a hose left on holds water right at the wall. AI-generated picture.

Rusted rectangular vent with its louvers shut in a brick wall above pine straw — A rusty foundation vent with its louvers shut. Walk the whole foundation, since one vent left open can blow cold air straight at a pipe. AI-generated picture.

Shut the vents

Look for: Walk the foundation and close each one you can. Clemson’s advice is closed in winter, reopened in spring¹.
What it tells you: Closed vents keep cold wind off the pipes under the floor. The vents stop covers the rest of the year.

Pipes in gray foam sleeves with taped joints running along wooden joists — Water pipes in gray foam with taped joints along floor joists. Clemson says insulated exposed pipes generally handle mild freezes down to 20°F². AI-generated picture.

Wrap what's exposed

Look for: Shine a light from the hatch for bare pipe, and check garages and exterior walls too. Gaps in the foam at elbows and valves are the usual misses.
What it tells you: Clemson says to insulate hot lines as well as cold ones, since hot lines can freeze quicker¹. Wrapping the pipes has the details.

Copper pipes soldered to a brass valve with a dark lever against a pale wall — Copper lines soldered to a brass ball valve. Try yours today: a stiff or stuck handle is better found in daylight, with no water on the floor.

Test the shutoff now

Look for: Find and test your main shutoff and the water shutoff at the heater before it freezes¹.
What it tells you: No shutoff of your own? A 2018 Columbia Water notice, reposted by local news, gave temporary permission to use the meter valve for those freeze days only³. Don’t assume that stands. Ask your utility, ahead of time.

Small plastic container with a white cap on a counter next to a kitchen sink — A small plastic container by the kitchen sink. A small cup and a watch will tell you how fast a faucet is running. AI-generated picture.

Set the flow with a cup

Look for: Time a 3-ounce cup under the faucet. Clemson says it fills in 5 minutes 37 seconds at 0.25 gallons an hour, and in 1 minute 24 seconds at 1 gallon an hour².
What it tells you: For a 1/2-inch pipe with 1/2-inch insulation and 20 feet exposed, Clemson gives 0.23 to 0.28 gallons an hour at 25°F, and 0.57 to 0.68 at 5°F². Four faucets at 1 gallon an hour for 10 hours use about 40 gallons.

Plain wooden shed with shingles and a metal well pipe among pines — A small pump house with a well pipe. The stretch between well and pressure tank is the part that sits still between pump cycles. AI-generated picture.

On a well

Look for: Check how well the line between the well and the pressure tank is covered, especially in a poorly insulated spot.
What it tells you: Water in that pipe moves only when the pump runs. Clemson suggests about 6 gallons an hour to cycle the pump in poorly insulated spots².

How cold does it have to get here?

Clemson says South Carolina winters seldom drop below 20°F, with single digits now and then. Pipe buried 12 inches should never freeze here, and the frost depth at Columbia is listed as zero². Your worry is the exposed pipe, not the line in the yard.

Yours to do

Wrap what you can reach without going under the house: garage lines and exposed runs at the wall.
Close the vents, unhook the hose at each outdoor tap, and test the shutoff.
Keep the flow going the whole time it’s below freezing².

For a licensed pro

Wrapping crawlspace lines you can’t reach from the hatch. Hire it out instead of crawling in.
Repairing any pipe that has split.
Checking an exposed well line and its pump if you are unsure of the insulation.