Inspecting field stone foundation

Many homes in my area are on stacked stones, often with no mortar. It’s normal in these foundations to have many large holes and to have poor contact with the structure. For those of you that inspect this type of foundation, at what point do you write it up as a problem? Is any unmortared stone foundation automatically in need of an engineer?

Not in my mind. If with mortar, patch voides as needed to maintain the structural integrity of the wall and keep critters out. If it starts wider and gets narrower as it goes up and hasn’t moved, I may recommend monitoring the walls and, THEN, if they move get a qualified stone mason in there. IMHO

P.S. Welome to our forum, Jack!..Enjoy! :grinning_face_with_smiling_eyes:

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If a home has that type of foundation it’s probably pushing a century in age. Think about that. If the house stood for a hundred years or more sitting on “rocks”, then it’ll probably stand for a hundred more… We have a ton of homes around here that are like that and the foundations are doing better than the homes themselves…


Hey Jack,
I agree with both above but like Larry said I always put it out of my report and flag it to be reported by a licensed stonemason. There’s a good clip on YouTube on repointing old stone foundations from this old house, it’s pretty good.
Best, Steve


Evening, Jack.
Hope this post finds you well.

There are all types of stone foundations. An image would help.

Field stone foundations are wider at the bottom than the top.
The top of the foundation should be level

Missing stone and gaps require repairs from a stone mason.

How to Recognize & Diagnose Stone Foundation Cracks, Bulges, Movement

Hope that helps.


I don’t have a picture of a specific foundation. I just wanted people’s opinion on reporting them in general. Most that I’ve seen don’t really change in size from the base to the top.