Crumbling foundations: Pyrrhotite in Connecticut: what it is, what to look for, what to do first
If your foundation was poured from the early 1980s on and the walls are cracking in a web pattern, testing comes before any repair. Here's how it works.
- Testing first, repairs second
- Programs that help with costs
- Plain answers, no sales pitch
What homeowners should know
Since the 2010s, thousands of homeowners in north-central and northeastern Connecticut have found their basement walls cracking in a distinctive web pattern. The cause traced back to pyrrhotite, an iron sulfide mineral in aggregate from a quarry in northeastern Connecticut that supplied concrete for foundations from the early 1980s on. When pyrrhotite meets oxygen and water it reacts and expands, and the concrete slowly breaks apart from the inside.
Warning signs
- Map-pattern or spider-web cracking on basement walls
- Horizontal cracks, often widest near the middle of a wall
- White powdery deposits or rust-colored staining at cracks
- Walls that bulge, flake or crumble when you press on the surface
Not every cracked foundation has pyrrhotite. Shrinkage cracks, settlement and water pressure cause most cracks, and they're usually repairable. That's why testing comes before any repair.
What to do first
- Don't patch or inject cracks yet. Repairs don't stop the reaction and can hide evidence a tester needs.
- Get a visual inspection from a licensed professional engineer.
- Core testing (petrographic analysis) confirms whether pyrrhotite is present and how much.
- Testing reimbursement: the Capitol Region Council of Governments (CRCOG) administers reimbursement for testing costs at foundationtesting.org. Terms have changed over time, so check the current program.
- Remediation claims for confirmed cases go through the Connecticut Foundation Solutions Indemnity Company (CFSIC).
The Connecticut Department of Housing keeps program information on its crumbling foundations page, including the towns identified as affected.
Where we fit in
We aren't testers and we aren't part of CFSIC. We pour foundations, footings and slabs, and we repair ordinary foundation cracks. If your house needs a foundation replaced under the CFSIC program, the work has to meet that program's requirements, and CRCOG publishes a qualified vendors list. For new foundations, additions, garages and non-pyrrhotite crack repair, we're glad to give you an estimate.
Towns in our service area within about 20 miles of the former Mottes plant: East Hartford, East Windsor, Manchester, South Windsor, Windsor and Windsor Locks.
Crumbling foundation questions
What causes crumbling foundations in Connecticut?
Pyrrhotite, an iron sulfide mineral that was in aggregate used for concrete in north-central and northeastern Connecticut. When it's exposed to oxygen and water it reacts and expands, cracking the concrete from inside over years.
Which homes are at risk?
Mainly homes with foundations poured from the early 1980s on, in towns that got concrete from the former J.J. Mottes Concrete plant in Stafford Springs. The state's first testing program covered homes within 20 miles of the plant, then widened eligibility by waiver.
Can a pyrrhotite foundation be repaired?
The damage is irreversible. Patching or injecting cracks doesn't stop the reaction. Where testing confirms a problem and deterioration is significant, the long-term fix is replacing the foundation.
How do I get my foundation tested?
Start with a visual inspection by a licensed professional engineer, then core testing (petrographic analysis) if needed. CRCOG runs a reimbursement program for testing costs at foundationtesting.org; check the current terms there.
Who pays for foundation replacement?
The Connecticut Foundation Solutions Indemnity Company (CFSIC) handles claims for qualifying homeowners. Eligibility and limits are set by CFSIC, so start with them once you have test results.