"We've got one where all the radiators are busted," said Wesolowski, whose business in based in Perry Hall. "You only need one break in an entire house to render your whole heating system useless."

Many problems are "things that can be avoided with just a few minutes of time," he said.

"The No. 1 thing you can do when they're calling for single digits is shut your water off at the main," Wesolowski said, adding that people should also turn the heat up a few degrees while they're gone from the house, and open cabinets to allow heat to circulate near the pipes.

And even then, said Tant of Len the Plumber, sometimes you will still end up with a burst pipe.

"You really can't say what Mother Nature is going to do," Tant said. "I've seen joists that were insulated, pipes that were insulated, and it still happens. Or all the abandoned homes in the city, their pipes will burst and flood, and it's the neighbors who suffer."

At Gaige's home in Severna Park, he sets about fixing the water pipe that leads to the outdoor hose bib. He removes 541/4 inches of copper pipe — there's some corrosion on the existing one — and replaces it.

"Now the fun part," Tant said, firing up his soldering torch to weld everything back together. At least for now, at least at this house.

"I tell my customers," he said, "a house is a never-ending project."