Courtesy of Karen Riani
In 2020, Karen Riani and her husband were doing what many families did during the early days of the COVID-19 pandemic: skipping a vacation to invest in home projects. But when they tore down some old basement walls, they uncovered a foundation riddled with deep, horizontal cracks.
“We just stared at each other and said, ‘This is not normal,’” she recalls.
They didn’t know what was wrong. Neither did her cousin, who worked in concrete, or the structural engineer they called to take a closer look. They then sent a core sample to a lab for testing, and when the results came back on Christmas Eve, they confirmed the Rianis’ worst fears.
Their foundation had tested positive for pyrrhotite, a little-known mineral that causes concrete to crack, swell, and eventually crumble. The only fix was a full foundation replacement.
For years, pyrrhotite damage was considered a crisis confined to Connecticut. But now, with cases emerging across Massachusetts, it’s clear the threat is broader—and growing. Thanks to advocacy from homeowners like Riani, the state is beginning to wake up to the risks. Still, she warns, there’s a long way to go.
Fool’s foundation: What is pyrrhotite?
Time for a science lesson: Pyrrhotite is an iron sulfide mineral closely related to pyrite (often called fool’s gold). While it might be prized by collectors and crystal enthusiasts, it poses a serious threat when it ends up in the concrete used to build home foundations.
The danger comes from how pyrrhotite reacts to water and air. When exposed to the elements over time, the mineral breaks down and forms secondary compounds that expand and contract, creating cracks in the concrete. Those cracks can grow slowly and sometimes invisibly until the foundation begins to crumble from the inside out.
Here’s where it gets more complicated: Concrete is made using a mix of cement, water, and crushed stone. If the stone includes rock that contains pyrrhotite that’s not detected before construction, that foundation is essentially a ticking time bomb. The damage often doesn’t appear for 10 to 20 years. But once it does, it can be catastrophic.
Homes with pyrrhotite damage are often uninsurable, unfinanceable, and nearly impossible to sell without full foundation replacement—at a cost that can reach $150,000 or more.
This isn’t just Connecticut’s problem anymore
Riani had never heard of pyrrhotite in Massachusetts homes before discovering it in her own basement. Neither had her structural engineer.
“He had no idea,” she says.
For years, Connecticut has been ground zero for the crumbling foundation crisis caused by pyrrhotite. Experts estimate that as many as 35,000 homes built between 1983 and 2015 in the northeastern part of the state could be affected. Thousands have already shown visible signs of damage, and many more are expected to follow in the coming years.
Riani’s case, however, drew attention to Central Massachusetts. In 2022, the state confirmed pyrrhotite in a local quarry, and since then, the number of affected towns has doubled—from 20 to 43.
“We now know that 23 of those towns have nothing to do with Connecticut,” Riani says. “We probably have at least three sources [of pyrrhotite] of our own in Massachusetts.”
She estimates that just in Holden, more than 1,300 homes were built during the years when contaminated aggregate may have been used. And the more people come forward, the more the map grows.
Still, fear and stigma keep many silent.
“So many of us have been told by various people, ‘Just cover it up and sell it,’” she says. “That’s why we advocate so strongly for buyers. You need to be safe because you don’t know. You may not see it.”
She’s not alone.
Keith Cloutier discovered his crumbling foundation almost by accident.
“It’s New England. It’s not untypical to see cracks in a foundation,” he says. But as the damage worsened, he began to suspect something deeper.
After comparing photos from the Connecticut crisis, he says, “My heart just sank. I closed my laptop and said, ‘This is exactly what my foundation looks like.’”
Confirmed cases have also emerged in parts of New Hampshire and Vermont. That’s not surprising when looking at the geology of the area. Pyrrhotite-bearing rock is found in a wide stretch of metamorphic bedrock that runs along the Appalachian Mountains.
In 2020, the U.S. Geological Survey released a national map identifying regions where this mineral is likely to occur. The findings show that the problem is not an isolated anomaly, but tied to decades of aggregate quarrying in the Northeast.
While Connecticut remains the epicenter of the crisis, the broader risk zone is expanding. With more testing and awareness, the number of homes found to have contaminated concrete is expected to grow in Massachusetts—and beyond.
Why insurance won’t save you
For many homeowners, discovering foundation damage caused by pyrrhotite comes with an even more painful realization: Their insurance likely won’t cover it. That’s because most standard homeowners policies exclude “gradual deterioration.” Unless a home collapses suddenly and completely, the cost of repairing a crumbling foundation is normally considered the owner’s responsibility.
Unfortunately, that risk isn’t always obvious.
The only way to officially confirm whether pyrrhotite is present in a foundation is through a petrographic analysis, a lab test that involves microscopic examination of the concrete. But these tests are costly, often running between $200 for an initial core test and up to $4,000 for additional testing.
That leaves many buyers and even sellers completely unaware that their foundation is built with fool’s gold.
Massachusetts steps up, but is it too late?
After years of growing concern, Massachusetts has taken its first formal step toward addressing the hidden crisis of crumbling foundations. Tucked into the state’s $61 billion budget deal is new legislation that creates a commission to study the presence and impact of pyrrhotite in residential construction across the state.
The commission’s task is to assess the geographic scope of the issue, evaluate potential health and financial risks, and begin shaping recommendations for how the state can support affected homeowners.
While the new law is just a first step, it signals a shift: Massachusetts is beginning to chart a path toward long-term remediation. That could eventually lead to public funding or state-backed insurance solutions, especially if the scale of the problem turns out to be as widespread as early indicators suggest.
Connecticut, where the crisis emerged nearly a decade ago, is further along. The state has already established a captive insurance company and a dedicated assistance fund to help homeowners pay for foundation replacements with grants of up to $175,000.
Massachusetts isn’t there yet, but this latest legislative move suggests the state is following a similar trajectory, recognizing that proactive intervention might be the only way to prevent financial ruin for thousands of unsuspecting homeowners.
The cost of taking action
And for homeowners whose foundations test positive for pyrrhotite, that help can’t come soon enough. The financial toll isn’t just steep, it’s life-altering.
Cloutier was quoted between $160,000 and $170,000 for a full replacement.
“It was either walk away from the house, file for bankruptcy, or find a way to pay for it myself,” he says. “There was no good option, just the least-worst one.”
He and his wife drained their retirement savings and borrowed against their home equity to cover the costs. But even after his foundation was replaced, the financial fallout lingered.
“I had to refinance into a 30-year mortgage just to stay afloat,” he says. “We lost our finished basement. I couldn’t afford to rebuild it. That’s just gone.”
Riani has a similar story. She and her husband tapped their savings and retirement accounts to replace the foundation: The cost was $280,000, 80% of their original purchase price.
What homeowners can do
For current homeowners, the first—and most urgent—step is testing. In Connecticut, the state offers up to $5,000 to cover professional assessments. But in Massachusetts, where the problem is newer, help is limited.
A recently passed law now mandates home inspections at the time of sale, which might catch visible warning signs like horizontal cracks or bowing walls, but these signs often don’t appear until it’s too late. The only definitive way to detect pyrrhotite is through a core sample and petrographic analysis, which isn’t part of a standard inspection.
For buyers, it’s worth negotiating. In high-risk areas, some have successfully asked sellers to pay for core testing as part of concessions. And whether you’re buying, selling, or already own in New England, it’s smart to consult the U.S. Geological Survey maps that highlight regions with a higher likelihood of pyrrhotite-bearing rock. A little research now could save you from a six-figure foundation bill down the line.