Footing (Rat wall)

Inspecting a house that was built around 1940. The buyers are getting a USDA rural development loan. The USDA requested from me a couple of things I don’t know.
Number #1 I understand , but #2 not so much what’s a rat wall

#1 Structurally sound does mean that it has to be a permanent foundation with a contiguous footer system and the block doesn’t sit on the ground.

#2 The concrete slab is acceptable as long as it has a rat wall that extends below the frost line. The inspector should be able to determine if it does have the appropriate rat wall.

Thank You In Advance

I’m guessing they mean stem wall.

It’s a concrete wall that goes around the slab and down through the grade to stop ‘rats’ and vermin from digging their way under the slab.


Where is this customary? We usually pour the footing monolithically with the slab. I’ve even done it that way when the frost line was 48"

What’s the Tennessee frost line? I cannot see how you could verify the wall depth without getting your shovel out…

Not sure exactly… I only heard about it from chap in Michigan a couple of years back as I recall. I will see if I can find any info on it.

Its a perimeter wall on the exterior of the home below grade.
Skip to about 50 seconds.

Better video

I doubt if those videos will make the cut into training classrooms…

How deep is the wall ?

TN frost line is 3", freeze depth is 12", minimum footings of 24" in middle TN.