RUST JACKING/STEEL EXPANSION:

Above are two different pieces of the bottom plate of a graduated steel beam taken from the exact same place, The Northeast Community Center. These above pictures show just how much steel can expand from "rust jacking". Over time the iron oxide, more commonly known as rust builds up pushing apart the wall. Originally installed the steel is 3/8 an inch as seen in the top left picture; however, in the picture located in the upper right you can clearly see the steel has expanded to nearly 2 inches. The high force expelled by rust jacking will start to push apart your walls, and eventually put cracks in the masonry, and or concrete. "Any ferrous material open to the environment is liable to corrode." As you can see in the top right photo there is a swimming pool in the background. The moisture of the pool definitely accelerated the beam/steel failure.

Below is another example of a 3/8 inch steel "rust jacking" to 1and 1/2 inches.