How to Prevent Pipes From Freezing and Avoid a Burst

Pipes freeze when the temperature stays low long enough, and the first ones to go are the ones the heat never reaches. Here is where those pipes are, when they are at risk and what helps before a hard freeze, plus the spots that are better left to a pro.

Which Pipes Freeze First

In most homes, the pipes at risk are:

• Pipes in outside walls, especially behind a kitchen or bathroom sink on an exterior wall
• Crawl spaces, where the lines hang under the floor with nothing between them and the cold
• Unheated basements, garages and utility rooms
• Mobile homes, where the supply lines run through the underbelly
• Outdoor spigots and the short run of pipe behind them

Copper and plastic pipes can both freeze, and plastic is the one more likely to crack. The pipes that fail are usually the ones you never see, behind the drywall or under the floor.

When Pipes Are at Risk

Pipes in unprotected spots usually start to freeze when the temperature drops below about 20 degrees, although it can happen a little above that. The exact number depends on three things: the wind, how well the pipe is insulated and how long the cold lasts.

A pipe in a crawl space with the wind blowing through can freeze at a milder temperature than a pipe inside a heated wall. Several hours of hard cold in a row is also more dangerous than a quick dip overnight. Plan on acting when the forecast shows a day or more of temperatures well below freezing.

Do You Need to Run Water to Keep Pipes From Freezing?

A slow drip helps, since moving water is harder to freeze. If a sink sits on an outside wall or a pipe runs through a cold area, let that faucet drip a trickle through the coldest nights. Cold water works fine. A trickle is plenty, because a steady stream only wastes water and strains the supply.

A few more steps that help:

• Open the cabinet doors under sinks on outside walls so warm air can reach the pipes
• Keep the heat on and steady, day and night
• Keep the garage door closed

Shutting off the water at the main will not protect the pipes by itself, since water left in the lines can still freeze. Know where your main shutoff valve is, though, so you can stop the water fast if a pipe cracks or bursts.

What to Wrap Around Pipes So They Do Not Freeze

Insulation slows heat loss from a pipe, but it does not add heat. It helps most on lines that get some warmth from the house, and it does little for a pipe in a space that stays well below freezing. It also only protects the pipes you can reach.

The lines inside a wall or under the floor are the ones most likely to be missed, and you cannot wrap what you cannot see. Wrap the exposed ones before the cold shows up in the forecast, not after.

If the Heat or Power Goes Out, or You Are Away

If you leave for a few days, keep the heat on and set the thermostat no lower than 55 degrees. That is a minimum, and pipes in an outside wall can still freeze in extreme cold.

If the power goes out in a hard freeze, close off the rooms you do not need and keep the heat in the rooms where the pipes run. Open the cabinet doors and let a faucet drip. If the outage lasts a day or more, call us and we will help you protect the lines. If you are on a well, an outage also stops the pump, so you lose water before anything freezes.

If a Pipe Freezes Anyway

If a faucet runs slow or stops in the cold, a pipe may be frozen. It can thaw on its own when the weather warms up, but a pipe that already cracked will leak once the ice melts, and that is a job for our water line repair team. Do not use a flame or try to rush the thaw, since heat applied too fast can break the pipe.

What We Check Before the Cold

As part of our plumbing services in Jefferson City, Columbia and the rural communities around them, we check your home for freeze risk. We start with where the supply lines run. Then we check which ones sit in an outside wall, a crawl space or an unheated area, and which ones have no protection at all. If one of them is a problem, you find out while the fix is still a small job.

If you have pipes in an outside wall, a crawl space or an unheated area, request a free estimate or call us at 573-301-0141 and we’ll check them before the cold arrives.