Patrick Springer and Charly Haley, Published September 24 2012
Experts: Water ground around foundation to avoid cracks
The clay soils of the Red River Valley act much like a sponge, expanding when wet and shrinking when dry.
The abrupt shift from supersaturated soils to bone dry conditions can cause the soil to pull away from basement walls.
If that’s happened, experts advise homeowners to water the ground around their foundation.
Sticking doors or windows, or cracks in walls or ceilings, could be a sign that a building is shifting because of soil shrinkage, warns Ken Hellevang, an engineer with the North Dakota State University Extension Service.
That’s what happened to the Fargo home of Mike and Connie Walsh, who are now having their basement and foundation repaired.
The Walshs noticed the hairline crack in their basement a couple of years ago, Mike Walsh, 69, said. He thought it was the concrete steps to their front door pushing on the foundation, so he jackhammered the steps away.
That didn’t solve the problem though, because “this spring, the doggone thing really opened up,” Walsh said.
Due to the dry conditions, part of their house’s cracked foundation sunk one-half inch into the ground, unleveled to the point that the Walshes had trouble using their front door, which is above the crack.
“We couldn’t get the front door shut,” Connie Walsh, 64, said.
Ted Dockter, 80, was having similar problems in his Fargo home.
“The west wall on the basement was pushed in an inch,” Dockter said. He also said a gazebo he’d built was sinking into the dirt, damaging his back patio.
To avoid problems during an extended dry period, Hellevang recommends that homeowners maintain relatively constant moisture content in the soil around the house.
He advises against watering directly into the gap, since there is a risk water could infiltrate the basement.
“We don’t really want to be running a bunch of water right down the basement wall,” Hellevang said.
Instead, he recommends soaking the ground one or two feet around a foundation. It might be a good idea to set a timer so you don’t forget, and leave the water running too long.
Use several applications, allowing periods of several hours in between to allow the ground to dry, enabling water to gradually seep down several feet.
But be warned: Don’t fill in the crack next to the basement wall with soil.
“When the soil gets wet,” he said, “it will expand, pushing on the basement wall, possibly with enough pressure to crack the wall.”
Donald Schwert, a professor of geoscience at NDSU, agrees that the drought has created soil conditions that pose risks for foundations, water lines and sidewalks – any infrastructure that could move as the ground shifts.
“This would include water lines, gas lines, sewer lines,” Schwert said. “It includes sidewalks, foundations, streets.”
Schwert agrees with Hellevang’s advice to keep the ground around foundations moist, which is especially important given the sponge-like behavior of the area’s clay soils.
“The more you can keep these clays up against your foundation, the safer the foundation’s going to be,” he said.
Don’t expect immediate results from watering around a foundation. “It takes awhile for these clays to expand and readjust,” Schwert said.
The Walsh home was too far gone to be fixed by watering the soil, so they hired Innovative Basement Systems to install foundation piers.
“We’re doing these kinds of repairs all over the area, all over the region this year,” said Charlie Adams, foundation specialist with Innovative Basement Systems.
Installing the steel foundation piers helps stabilize the foundation by transferring its weight from the surrounding soils to the piers, Adams said.
Dockter had the same process done on his house in the spring, he said, and he’s hoping it will prevent future problems.
The Walshs were happy with the work being done on their home.
“That’s the good part. You hate the mess, but it’s nice to use the front door,” Mike Walsh said.
Although the dry soils are the most severe in recent years, conditions were much worse during the extreme drought of late 1988-89, Schwert said.
“We had much more severe conditions in the 1980s, and it included severe foundation damage in the Fargo-Moorhead region,” he said.
So far, Schwert added, he’s not aware of that happening, but he would not be surprised if damage is occurring.
Hellevang also hasn’t heard of major problems yet, but said conditions are bad enough that it’s time for homeowners to be vigilant and to take action.
One Fargo homeowner called when his doors and windows had shifted, but reported back that several days of watering returned them to normal, Hellevang said.
Lower water levels on the Red River mean slumping along riverbanks will occur, Schwert said. That’s because the water is not pushing against the bank, as it is when the river is higher.
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Readers can reach Forum reporter Patrick Springer at (701) 241-5522