Trying to identify foundation walls

My husband, son and I are studying home inspection. We are using three buildings we own to practice on.

We can’t identify the material in the foundation walls. It is not talked about in the course we are taking. The building is in Philadelphia, PA. It is a two and 1/2 bedroom row house over 60 years old, perhaps close to 100 years old. It is midway the block in a row of approximately 70 like homes.

Where the plaster has fallen off the basement walls you can see large grey stones each around a foot long but not at all uniform in shape or size. The stones rest in what appears to be bright rust red grainy dirt. Although the stones seem securely set, the red dirt is easily scratched out. It is slightly damp.

What might these foundation walls be called?
Where can you find out the age of a house?
If a group of row homes, appear not to have been built with toilets, where where the outhouses in an urban area? (back yard? down the street?)



my first guess is fieldstone

does it look like a bunch of stones piled up and mortared together?

i’ve never seen red mortar, so that i cannot comment on.

Photos would be most helpful.

Look like this? It is a common stone foundation.

Yes…fiedstone…it seems as though I heard this somewhere…

The rust red “dirt” appears to be the only “mortar”…

Jason1, your picture is helpful, sorry I’m not up with digital photos yet, lost my USB cord to the camera… These are similar to the stones in your photo, however there is 2 to 4 inches of “dirt” between each stone

Thank you for the reponses. I did a seach on fieldstone and asked a couple people… yes thats what it is! I’ll research on my own what the mortar is and issues unique to this type of foundation.



Does it look like this?

Hello Monica, might I suggest that you also contact someone in your local that is familiar with the local construction practices for that period of time. Look for a historical building group or even a contractor that specializes in this type of building.

The stone may be limestone, often this can be found used in homes even in my part of central PA, however sandstone is more previlent.

What concerns me the most is the thickness of the mortar joints, I am somewhat familiar with older masonry homes and stone foundations and this sound quite odd. I would approximate the largest average mortar joint I have seen as being approximately 2 inches. I would also be interested to learn more about your statement that the mortar appears to be moist, is this normal or is there a water source coming from maybe the next building.

Remember, just like now, back in the good old days builders still followed the basic rules of…

  1. Don’t worry it will be covered
  2. Good enough, it aint my house
  3. What are you worried about, you can’t see it from your house
  4. You can’t see it from my house.

I have the picture in email as a bitmap and jpeg, I couldn’t load it to the site, emailing it to those who posted (hope ya don’t mind):lol: …didn’t realize I could put my camera media directly into my laptop…Dooh!


Mortar has fallen out of this neglected stone foundation. *Photo: William Kibbel *

Does it look like this?

Marcel :slight_smile: :slight_smile: