The Brick that Built our City: Chicago Common


Tuesday we wrote about brick as a building material.  Today we feature one specific type of brick, Chicago common, which is a literal building block of this city.  Manufactured here in Chicago to feed the building boom after the Great Fire, Chicago common brick was used for the structural walls and alley exteriors of countless buildings here in the city.  Its still holding up the roofs over our heads and now it is also prized as a reclaimed building material.  

You may not have known that Chicago common had you surrounded … now you do.

Where can you find it?

You’ll find this ubiquitous building material just about anywhere in Chicago’s neighborhoods.  You’re not likely to see it in the brick building fronts facing the street (more on this below) but the side and alley walls of every brick building in the city more than 50 years old will show it. 

Chicago common also accounts for most of the exposed brick interiors you’ll find around the city in older buildings – in those cases the wall was generally covered by plaster originally and the brick was not meant to be exposed. Its purpose might be structural or it might have been serving as a 12″ thick interior fire wall – another relic of Great Fire nerves.  

brick at bar pastoral

What makes Chicago Common Brick unique?

The local clay that made up Chicago common brick was deposited in this region by glaciers in the last ice age.  Blue in its natural form, it turns a buff or salmon pink when fired (headed in a kiln for several days above 1500 degrees).

The bricks are varied in shape and coloration which made them visually unappealing to people excited about the start of the industrial age.  Builders of Chicago’s brick city scape paid through the nose to have more regular colored and shaped “face” bricks shipped in from other regions to construct the fronts of their houses, apartments and shops.

These days we find irregularity beautiful and machined objects boring so the visual variety of Chicago common has shifted from prosaic back alley material to valuable find.

Reusing Chicago Common

There’s no way to count how many buildings made of Chicago common are still standing but the number is certainly in decline.  The last manufacturer of these bricks closed in 1981 and brick buildings are demolished in Chicago every day.  An industry has spring up around salvaging bricks from these tear down buildings.  People use them for decoration, for walk ways, for garden walls and even for new construction.

A few years ago, Chicago Reader published a feature, Brickyard Blues, on the bricks and their history and future.  Devastatingly sad at times, it profiles a number of brick “stackers” who work on demolition sites, picking up, cleaning off mortar and stacking bricks in pallets of 1000 (for a mere 10 dollars a pallet).  We love the idea of re-using (rather than landfilling) these bricks, but the way they are reclaimed borders on the inhumane.  

Caring for Chicago Common in your building

While we’re all for re-use, preservation is still better.  This article written by Chicago building inspector, William Decker, of Decker Home Services, points out a few more of Chicago common’s unique characteristics.

This brick is softer, more absorbent and more breathable than other types of brick and it needs to be cared for in a different way.  It is generally important in any brick wall for mortar to be weaker than the brick (its much easier to repair than it is to replace the bricks themselves).  Chicago home owners need to watch out for mis-informed masons who want to repair or cover the mortar with Portland cement based mortars that are too strong for the brick and will cause water damage and eventually crack brick faces right off.

So there you have it.  Go on a scavenger hunt for Chicago common in your vicinity and you’re almost sure to find it down the first alley you explore.