Horizontal Black Line in Foundation

**Gunnar Alquist** · 07-23-2010, 07:31 PM

Never seen anything like this. 1955, single story ranch home. At the right/front exterior foundation stemwall I found a line that had been painted-over. When I chipped a bit of the paint off, I found black asphalt or tar. Looked and felt like the stuff used for a T&G roof. Then, when I was in the foundation crawlspace area, I found another larger line in a different area.

We do have some fairly expansive (adobe-type) soils around here, but there was no evidence of excessive foundation movement. Looks to me like it was originally poured this way. Seems to me that the seismic resistance of the foundation is compromised.

Foundation was bolted at some areas, but I could not find any bolts in the area of the second two pics. The first two pics are at the exterior of a slab section, so bolting could not be verified. Jerry Mc offered an observation that this upper layer is pretty much horizontal and might have been poured to raise the stemwall, like they originally poured it short.

Anyone ever seen anything like this before?
Anyone have any idea as to why this was done?
Any thoughts or suggestions? I will probably defer to a structural engineer, but I am still curious.

Thanks.

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**Ken Rowe** · 07-23-2010, 08:54 PM

I'd defer to a structural engineer. But, if I saw a poured foundation in a 1955 home in MN I'd suspect the foundation was rebuilt or the house moved to a newer foundation. Everything around here built in the 1950's is block.

Elliot Franson · 07-24-2010, 06:14 AM

Jerry Mc offered an observation that this upper layer is pretty much horizontal and might have been poured to raise the stemwall, like they originally poured it short.

Mr. Alquist: I do believe that Mr. McCarthy is right.

**John Kogel** · 07-24-2010, 07:59 PM

Jerry Mc offered an observation that this upper layer is pretty much horizontal and might have been poured to raise the stemwall, like they originally poured it short.
Mr. Alquist: I do believe that Mr. McCarthy is right.

Originally Posted by Elliot Franson

Mr. Alquist: I do believe that Mr. McCarthy is right.

In which case, we can think of no good reason for the tar.

**wayne soper** · 07-24-2010, 08:47 PM

When in doubt and poured the first part too low.
Drink, Drink, Drink, Pour tar, Drink, drink, Drink, Pour concrete.
Get er done bubba.

Mabey Tar goes well with Asbestos!!

**Billy Stephens** · 07-25-2010, 02:07 PM

Originally Posted by Gunnar Alquist

. 1955, single story ranch home. At the right/front exterior foundation stemwall

, I found black asphalt or tar. Looked and felt like the stuff used for a T&G roof. Then, when I was in the foundation crawlspace area, I found another larger line in a different area.

. Looks to me like it was originally poured this way.

might have been poured to raise the stemwall, like they originally poured it short.

Anyone ever seen anything like this before?
Anyone have any idea as to why this was done?
Any thoughts or suggestions? I will probably defer to a structural engineer, but I am still curious.

Thanks.

.
Moisture Intrusion Barrier between Concrete Cold Joint Pour.
.
.