What Can We Tell from This Photo? (Case Study 7)

Posted by in Cracking, Masonry, Simple Forensic Methods | April 20, 2015

 

This concrete block wall exhibits an unusual pattern of cracking.

 

Figure TLW-1 Wall exhibits vertical and horizontal cracking.

 

Figure TLW-2 Wall lifted and patched at left side vertical cracking.

 

What can we tell from these two photos?

  1. The line of the horizontal joints and the line at the top of the wall indicate that wall has been lifted at the right side vertical crack and even more at the left side vertical crack.
  2. The most severe lifting has occurred at the left side vertical crack.
  3. The wall has been pushed inward, thus the inward movement has been caused by something on the exterior face.
  4. The cracking has been progressing for some time as evidenced by the patching and the paint coverage of the patching.
  5. There are no apparent vehicle impact marks on the interior face of the wall.

 

Figure TLW-3 Large tree against exterior face of wall.

What can we tell from this photo?

  1. There is a large tree behind the wall that has pushed a fence over.
  2. The large tree is located at the left side vertical cracking.

Conclusion:  The tree has grown into the wall pushing it inward and the roots have grown under the footing lifting the wall upward.  Since trees generally grow slowly and the cracking exhibits patching, this has been present and progressing for years.

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