In some parts of the Southeast, extreme drought has made house foundations more vulnerable to sinking, cracking and leaking. The problem is occurring mostly in areas that have clay soils.

"When the soil dries out, it contracts and pulls away from the foundation," said Tim Slater, owner of Tri-State Waterproofing in Lula. "The ground also develops cracks, which, when it finally does rain, allow water to flow freely against the foundation."

That may not be an issue if your home has a strong, waterproof foundation, which many houses don’t.

"All concrete walls have small hairline cracks," Slater said. "Once water finds its way in, it opens a path, and it will continue to find that path."

With enough rainfall, the shrunken soil will expand and fill cracks in the ground, but the fissures reappear when the ground dries out again.

Slater said the most vulnerable homes are those built before 1980, when most foundations were built on cinder blocks rather than poured concrete.

"Often those same houses don’t have good drainage technology," he said. "If the drainage system gets clogged up, the ground becomes saturated. Then the foundation sinks and walls can start to cave in."

Lamar Carver, manager of inspection services for Hall County, said drought-related foundation failures appear to be an isolated problem in Hall.

But then, the area has never dealt with a drought of this magnitude before.

Homes that have held up fine for decades may be compromised if current conditions persist.

"Clay soil may not be as stable when it loses its moisture content," Carver said. "That’s why, for a new home or a major renovation, we rely on structural engineers to tell us the bearing capacity of the soil."

But without a drenching rain, there is no way to test the integrity of the foundation.

"A few years back, we had a number of homes that were built during the drought (of 1999-2002), and no one knew they had foundation or drainage issues until we started getting rain again," Carver said.

Slater said he’s observed the same phenomenon.

"We were working seven days a week after the hurricanes in 2004 and 2005 (which followed a four-year drought in Georgia)," he said.

And now, some residents are discovering leaks they didn’t know existed. "We had five repair jobs just out of that last little rain we had (Oct. 24-25)," said Slater.

Dan Power, owner of Dan Power Construction in Gainesville, said he’s handled two cases recently.

"Both were older homes in the city of Gainesville," he said. "Both had cinder block foundations, didn’t have a drainage system, and their waterproofing was just tar, not any kind of sealant."

For those homes, Power had to jack up the foundation and put down new layers of concrete, then add waterproofing and a drainage system.

"It’s labor-intensive, because in these older neighborhoods you can’t just come in with a bulldozer and dig everything up," he said. "You’ve got old lines — gas, water, phone, cable — that you’ve got to work around. It’s a hard job, and a lot of (contractors) don’t want to fool with it. It’s easier to work on new construction."

A major overhaul of a foundation can be expensive, and is generally not covered by homeowners’ insurance.

"Sometimes the solution to a foundation problem can be as simple as fixing a crack for $300," Slater said. "But if it requires a full foundation excavation, that’s going to cost about $10,000 for the average home."

Larry Bowman, a civil engineer in Oakwood, said homeowners should consider all their options before taking the drastic step of raising the entire house.

"Usually our aim is to stabilize the home from further settlement," he said. "You can sometimes cause more damage by jacking it up."

Bowman said people should suspect their foundation is settling if they notice large cracks in sheetrock, or if doors no longer close properly.

He said the two most common methods for dealing with a sinking foundation are pressure grouting, in which concrete is injected into the ground, or drilling to insert helical piers as anchors.

Carver said foundation problems may be relatively rare in Hall because most of the county’s housing stock is new.

Power agrees that failures are uncommon in newer homes, but even a brand-new house can suffer damage if it’s poorly constructed.

"When we do start having rain, people may start noticing all kinds of problems," he said.