Across western and central Massachusetts, some homeowners have faced a costly and surprising problem hiding beneath their homes. The issue is concrete foundations that begin to crumble from within. The cause is a naturally occurring mineral called pyrrhotite. Understanding this problem helps protect your home’s value and gives you confidence when buying or selling.
Pyrrhotite is an iron sulfide mineral that can sometimes be found in the rock used to make concrete. When exposed to oxygen and moisture, it reacts and expands. Over time this causes the concrete to crack, flake, and weaken from the inside. The process is irreversible and often takes decades to appear, but once it begins the only lasting solution is to replace the affected concrete.
This issue has been confirmed in Hampden, Hampshire, Worcester, Franklin, Berkshire, and Middlesex Counties. Homes built between the 1980s and early 2010s are at higher risk, depending on where their concrete materials were sourced.
The Massachusetts Legislature created the Special Commission on Crumbling Concrete Foundations in 2018 to study the issue. The Commission’s 2019 Final Report confirmed that pyrrhotite-related deterioration exists in parts of the state and recommended increased testing, homeowner support, and awareness.
Massachusetts has since launched a testing reimbursement program to help homeowners pay for professional inspection and lab testing. The program details and forms are available here:
👉 Crumbling Foundation Testing Reimbursement Application (mass.gov)
Homeowners and buyers should watch for these warning signs:
Cracks that form in a “map-like” or “spiderweb” pattern in basement walls
Flaking or bulging areas on the foundation surface
Concrete that crumbles near basement windows or bulkhead openings
If these symptoms appear, contact a structural engineer or foundation specialist for evaluation. Only laboratory testing can confirm the presence of pyrrhotite. Home inspectors and municipal officials can point out potential concerns but cannot provide a diagnosis.
Real-estate professionals like me now use a Concrete and Foundation Advisory and Disclosure form in these counties. This disclosure helps ensure that:
Buyers understand the potential risks of pyrrhotite contamination
Sellers share any known testing results or repairs
Agents stay within their professional limits and refer clients to qualified engineers
For sellers, proactive testing and documentation show transparency and protect both parties. For buyers, thorough inspection during the due-diligence period is essential.
Monitor regularly. Check for new or changing cracks in your foundation.
Test when uncertain. Early detection allows time to plan and apply for reimbursement.
Keep documentation. Save reports, photos, and invoices for any inspections or repairs.
Ask questions. If you are buying in one of the listed counties, ask about any known testing, repairs, or special assessments related to foundation issues.
The full extent of the pyrrhotite issue in Massachusetts is still being studied, but awareness and early testing are the best tools available to homeowners. The state’s resources and increased public education are helping to limit the impact on future homeowners.
As a local Realtor, I believe that understanding and sharing this information protects property values and promotes an informed, confident real-estate market. If you have concerns about your home or a property you plan to purchase, reach out to a licensed structural engineer or use the state links below for more information.