In thousands of homes across Connecticut, homeowners are discovering naturally occurring iron sulfides called pyrrhotites in their foundations. These sulfides, when exposed to oxygen and water, tend to result in crumbling foundations. This is because the sulfates take up more space than the original iron sulfides, causing the foundation to crack.

Some homes are more susceptible to crumbling foundations than others. If you are looking to evaluate your own home for foundation issues, here are 5 of the most important signs of pyrrhotite issues in your foundation:
Exterior Grading
Always look at exterior grading and gutter systems because water can initiate problems with pyrrhotite. You want to make sure that the grading pitch is away from the house and the gutter extends out at least three feet from the foundation.
Parge Coating
Parge coating is a thin coat of concrete put over the surface of the concrete for aesthetic purposes. Check outside of the foundation for parge coating that may be cracking or breaking off, and if so, check the foundation behind the coating.
Efflorescence
View the interior foundation for efflorescence. Efflorescence is a white, chalky, or crystal substance that is found on foundations when water has gotten into it and dried up.
Sandy Coloring
Search the foundation for a sandy or peachy color. This discoloration is normally found in blotches where the pyrrhotite has converted to iron sulfate.
Cracks
With high powered light, look at the foundation for cracks. This can be extremely tricky and really deserves a trained professional, as most people can misdiagnose mapping cracks in their early stages.
It used to be thought that horizontal cracks were bad and vertical ones were okay, but this is no longer the case. Vertical cracks can eventually map off if there is a pyrrhotite presence within the concrete foundation. This is just one example of why having a professional review further is important.
How to Make Foundation Repairs More Affordable
In Connecticut, there is a program set up by CFSIC (Connecticut Foundation Solutions Indemnity Company) that is in charge of allocating the funds related to crumbling foundations. If you are purchasing a home with potential foundation issues and want to get funding at any time in the future, you must do one of the following:
- Have the foundation evaluated by either a professional engineer or a certified foundation inspector listed on the CFSIC website
- Have core samples taken and submitted to CFSIC
If you do not do one of these two things, you waive all rights to future support from the CFSIC program.
For more information regarding foundation inspections, call Sherwood Inspection Services at 860-646-9983.
Comments 1
Thank you for explaining that any cracks, vertical or horizontal, can be a sign of something wrong with your foundation. My husband and I were walking through our basement and noticed some cracks along one of the walls. We’ll be sure to call someone in soon and see what we can do about getting it fixed before we start the process of finishing everything.