Demolishing and replacing concrete foundations has become something of a cottage industry for contractors in northeastern Connecticut and south-central Massachusetts. 

The foundations beneath upward of 6,000 homes built there between 1983 and 2015 are crumbling or are at risk, the result of a mineral called pyrrhotite found in the crushed rock aggregate from a single stone quarry in Willington, Connecticut. Connecticut issued more than 34,000 residential building permits within a 20-mile radius surrounding the quarry from 1983 to 2000, although it is unknown how many of those concrete foundations contain pyrrhotite, according to FEMA, the Federal Emergency Management Agency. 

While the problem is predominantly in these two Northeastern states, a U.S. government map shows potential pyrrhotite locations from Maine to Alabama. And thousands of foundations in Canada also are affected and there could be many more. 

When used to mix concrete that is poured into foundations, the unstable mineral reacts to exposure to oxygen and water by expanding, which causes cracking, peeling and crumbling over time—sometimes 15 to 30 years after the home was built. 

“It’s horrible,” John Sharon, owner of NE CT Concrete Foundations in Tolland, Connecticut, said. “It’s expensive.” 

The cost of tearing out and replacing a tainted foundation can run as high as $190,000 and involve lifting the house off its foundation and supporting it for weeks to months during excavation and construction. That price does not include expenses for the homeowner’s temporary relocation or for damages to the house beyond the foundation, even though the swelling concrete can cause granite countertops to crack, floors to warp, and windows and doors to refuse to close. 

Replacing a crumbling foundation is “not a simple thing,” noted Kevin Childree, the office manager for family owned Don Childree General Contractor in South Windsor, Connecticut, which has replaced more than 200 pyrrhotite-infested foundations since 2002. “Nobody knew what (the problem) was back then,” he said. “We knew it wasn’t good,” Childree’s father, Don Childree, added, “but we just didn’t know what it was.” 

“It’s an incredibly hard job, some of the most difficult projects that anybody could get into,” agreed Jamie Savage, owner of Savage Concrete in Southington, Connecticut, who replaced the foundation under a small room addition for $90,000. “That’s why it costs as much as a house does.” 

Still, more than 50 Connecticut contractors, including concrete companies, homebuilders, excavators, house-lifting specialists and others, appear on a list of firms approved for the work by the state-created Connecticut Foundation Solutions Indemnity Co.—or CFSIC—which is funded by the Legislature to help homeowners pay for foundation replacements. Don Childree estimated that at least another 50 are making repairs for homeowners who are paying themselves rather than waiting up to three years for state funding. 

“There used to be three of us that did it around here,” he said, but noted, “It’s a lot of people without a lot of experience doing it.” 

The usual remedy is to dig out the entire foundation, including footings, and start from scratch with clean concrete. Usually, a general or concrete contractor oversees the job and hires subs to lift the house or demolish the damaged foundation. Some, like the Childrees, invest in excavating equipment.  

“You have a house sitting on top of it, which makes it a lot more complicated,” noted Don Childree, who explained that the furnace and water heater have to be removed and pumps installed to control groundwater and rain from flooding the open pit during construction. “Everything’s out,” he said. “There’s a lot more work than just pouring the foundation.” 

Kevin Childree, whose 45-year-old family business traditionally specialized in home renovations and remodeling, said the bulk of the company’s business now is replacing pyrrhotite-damaged foundations. 

On the other hand, Savage, an independent contractor who often does sidewalk demolition and replacement and foundation repairs, said he gets just a few calls a year from afflicted homeowners but doesn’t take jobs from those who will rely on the CFSIC, which requires them to hire bonded contractors, to help them pay for the work. Private insurance companies are not required to cover pyrrhotite-related foundation repairs. 

Once he secures a bond and expands his business, Savage said, he will use shoring towers to stabilize the houses rather than lifting them.  

“It’s an opportunity,” he said of the scope of the pyrrhotite damage in Connecticut. “It does pay pretty decent.” 

Sharon, who has replaced 93 pyrrhotite-plagued foundations, also uses an alternative to lifting the house. 

The retired pilot, who started his business in response to the need for crumbling foundation replacements, removes the bad concrete and pours quick-drying replacement footers and floors. But he installs foundation walls premade from a fiberglass composite with a closed-cell foam core instead of concrete. The Epitome panels, made by Composite Panel Systems in Eagle River, Wisconsin, have an R-16.5 insulation value and come with a 15-year warranty. 

Sharon said the cost of the job is comparable to one using concrete, but the family does not have to move out of the home during construction, saving the homeowners the cost of temporary lodging. Plus, Sharon said, the work takes about four weeks, substantially less time than a concrete demo and replacement. 

Still, Sharon said, he “way underestimated the dynamic of the customer being home” during construction. 

“They’re angry, they’re depressed, they’re mad, they’re emotional about it,” he said. “We’re destroying the foundation of their house. It’s not natural, you know?” 

No end in sight 

And it’s far from over.  

“Houses built in 2010 up to 2015, those are houses that have yet to show any severe signs of concrete failure,” concrete consultant Kevin Miller of KE Miller LLC in Stonington, Connecticut, said. “In the next five years, they could be popping up.” 

In Massachusetts, where the state pays for pyrrhotite testing but has not created a fund to help homeowners replace damaged foundations, some suspect that the offending material might have come from quarries within that state and not just from the lone source in Connecticut—which is widely blamed for causing problems in both states. 

“They are starting to see some homes in other regions that are too far outside that area where the concrete would have been delivered,” Nick Scaglione, president of Concrete Research and Testing in Ohio, told a group of Massachusetts homeowners in October. 

In fact, the U.S. Geological Survey published a map in 2020 that showed potential pyrrhotite locations along the core of the Appalachian Trail as far north as Maine and as far south as Alabama. In Canada, the foundations of an estimated 8,000 homes could be affected. 

How many foundations will crumble, however, is anyone’s guess, especially because even concrete that tests positive for small amounts of pyrrhotite might not deteriorate. 

Winnie Tsen, an assistant director at the U.S. Government Accountability Office, said one contractor she spoke with compared the testing to screening for a cancer gene. 

“You may test positive for the gene and never have cancer for the rest of your life or may not test positive for it and develop it later,” she said. “Same thing: A foundation may have pyrrhotite in it, but it might never affect it.” 

Still, advised geophysicist Christoph Geiss, a professor of physics and environmental science at Trinity College in Hartford, Connecticut: When symptoms appear, “get all the pyrrhotite out.” If the replacement concrete is “clean,” he said, the new foundation has “just as much risk as any other foundation.”