Re: Sinking Block in Humboldt Park
Date: November 10, 2014 05:49PM
I went over and took a look, and saw a tempest in a teapot.
8 different buildings with similar characteristics that I think are the cause of the problems.
All with shallow basements (read shallow footings), Massive masonry porches with open/unconditioned stairs to the basement beneath them. All face the park and have nothing to break the wind.
The sidewalls showed no cracking. Only 1 of 8 showed any settling problems not related to the porch. Only 1 (different one) has had any serious work done to the porch in the last 30 years and I couldn't tell how well it was done.
Although Chicago's minimum depth for footings is the 42" frostline, that assumes both sides are protected from the weather.
In the case of the basement stairs, the footings are 4 feet from the weather on the dirt side and 6 inches from the weather on the stairwell side.
A hundred years ago, the builders should have set the porch footings a couple feet deeper. Now (possibly aggravated by the polar vortex), they are heaving.
Except for the one guy, everything I saw could be explained by differential settling of the buildings and the porches.
That one guy has bigger problems.