Undermined slab

Hi guys,

I ran across this in an inspection yesterday. I was crawling around in the crawl and in the far corner I see a HVAC supply trunk running through the block foundation to the “new” addition that was built 15 yrs ago. After further examination, it appears that they dug a tunnel underneath the existing slab roughly 3’ x 3’ x 10’ long to the new addition that was built beyond this tunnel. I could see the metal lathe of the slab.The whole slab part used to be part of an eat in kitchen area. That area was roughly 10’x12’ This was for a maintenance inspection. They had the house inspected before they bought it a year ago but always felt that the inspector didn’t do a thorough job. I believe that it’s a structural issue and should be differed to a SE. But it has also been that way for 15 years. Has anyone else run across underming of slabs such as this. I just want to see what other inspectors would say about this.


Hi. Louis

Although this scenario has been active in this condition for fifteen years, it does not make it right to the standards of the industry.

It would be best to just note that it is not customary to tunnel underneath slab on grades that were not designed for this purpose and recommend evaluation by an SE or a prominent General Contractor.

I can diffenitely see the wire mesh re-inforcement in the slab that was originally on the ground when the slab was poured and not where it belongs.

JMO Marcel :slight_smile: :slight_smile:

Thanks Marcel. I agree.

We dig tunnels under slabs all the time here. Typically they start on the Mexican side of the border, go under buildings, under the Tijuana River, and under buildings on the American side. Usually the tunnels are used to move drugs from Mexico to America. :margarit:

…and Mexicans! :smiley: :smiley: :smiley:

Naw. The Mexicans tend to swim the river, run the back country, or pile about 30 into a 40-year-old van that can’t do more than 40 miles per hour. That’s how the Border Patrol catches many of them, by tracking slow vans on the freeway.

Funny stuff. ROTFLMAO

This is NOT funny. I take offense to this type of sterotyping. I have a slow van…:slight_smile:

But is it 40 years old, Mark?