Chicago's Fine Old Brick Buildings in Danger

By
Home Inspector with Decker Home Services, LLC IL Lic # 450.002240

Chicago's brick buildings in peril

Chicago is, mainly, a brick city.  Oh, sure, there thousands of wood frame and brick veneer houses and buildings throughout our city, but travel the neighborhoods (Chicago is also a city of neighborhoods, from Lincoln Park to Beverly).  Most of this city was built with bricks and mortar. Properly built masonry buildings need very little repair or maintenance but, as these houses age it is obvious there will be needed repairs.

And therein lies the problem.

Seems simple enough, doesn't it?  Take out the old stuff and put in some new stuff, or smear some new stuff over the old stuff. The problems come from the "stuff". Most folks don't realize it, but the masonry materials we use in modern construction are completely different, (like, down to a molecular level different), than the materials our masonry homes were built with several decades ago.  And, many times, the new "stuff" is not nearly as good as the old stuff was.

Chicago was built with brick.  This is, in large part, because of the Great Chicago Fire of 1871.  Hundreds were killed and over 4 square miles of the city were completely destroyed.  The fire's northward expansion stopped at what has become a famous landmark, the Chicago Water Tower.

 Chicago Water Tower

And, please notice, the Water Tower is built from masonry.

This building boom lead to the use of what has become known as Chicago Common Brick.  Made from very high organic clay (a waste by-product of the construction of the Illinois & Michigan Canal) this brick is very durable.  It is also softer and more absorbent than modern brick.  It also expanded and contracted with atmospheric changes, so it was necessary to use a softer mortar that had similar expansion characteristics. The mortar that was used in the original construction was lime based, either lime mortar, or a mixture called lime putty.

Lime rich mortar has several characteristics that are completely different than modern Portland Cement, additive laden mortars. As water migrates through lime mortar, some of the lime is disolved and will travel with the water and refill small cracks that occur due to normal settlement (called autogenous healing). Lime mortar will expand and contract to account for movement caused by atmospheric changes. Lime mortars cure by carbonization (from contact with CO2 in the air) rather than by hydration, as modern Portland Cement mortars do.  It also was compatible with the moisture permeability of the bricks so water was absorbed and evaporated equally from both materials. The older (solid stone) masonry would also absorb some amount of moisture, but the sheer mass of the wall would limit the amounts of moisture & the depth of penetration, and the moisture will evaporate back out of the wall with atmospheric change.

In the 1930s, Portland Cement mortars were introduced.  They are hard, brittle, and moisture resistant. When new Portland Cement mortars are laid over the old original lime mortars, the water resistant mortars act to traps water in the wall.  When the walls freeze and thaw in winter, the retained water expands and the walls fracture and fall apart.  Building owners see the deterioration occurring, and mistakenly think they need to add more and more Portland cement to "keep the water out".  What they are actually doing is keeping the water "in"!  Additional repairs with modern mortars accelerate the deterioration of the wall, as each new application seals the wall tighter and tighter. The end result is substantially damaged masonry.

I have, personally, seen 100 year old brick buildings, whose parapet walls were "rebuilt" using the standard Portland Cement mortars available today, where the rebuilt portion has literally disintegrated in 4 to 6 years!  Modern masonry techniques are, literally, destroying these old buildings and houses.

Many restoration masons utilize modern Portland cement mortars because they are readily available at the big box stores, they are fast to mix and apply, and most significantly, the masons don't have a clear understanding of what is necessary to perform a proper long lasting repair in the first place. In the end, the less savvy building owner thinks that since the entire wall is clean looking and appears to have been "re-pointed" uniformly, he has received a good and very affordable repair. In fact, what they receive was a cosmetic overlay, which in most cases, accelerates the deterioration of the masonry.  Also, with the recent influx of Eastern European masons, their common practices are not proper for the Chicago style of building.  They, regularly, add additional sand to the mortar, hoping that this will add strength.  In fact, it makes the mortar mixture more water permiable.  This allows more water to be retained by the building's brick. 

The most common result of improper mortar application is that the thin layer of parge mortar cracks & falls off within a few years. In the areas where the new mortar extends deep enough to remain in place, moisture tends to be trapped in both the mortar bed joints and the edge surfaces of the brick. This causes the moisture laden brick to deteriorate through the expansion that occurs as it freezes. This condition is called spalling. Entire faces of brick can literally begin to progressively flake off.  In many cases, the trapped moisture will cause entire sections of brick to bulge out away from the building due to freeze/thaw cycles. In both cases, the result is substantially damaged masonry.

And, as icing on the cake, the winter of 2008 - 2009 had a record number of freeze/thaw cycles, and 2008 saw record rainfall levels.  Talk about a perfect storm!

The other large problem with old masonry is the steel lintels over the windows and doors. Over the years, moisture migrates into the wall, where it attacks the steel and causes it to rust and delaminate. When the steel delaminates, it flakes and expands, very slowly, but with thousands of pounds of force. The expanding steel causes the brick around the windows to bulge, and causes decorative stonework to crack. The most common (and mistaken) repair is to caulk or grout the spaces between the lintels and the masonry and seal the lintels, which the repairman thinks will keep water out of the wall.  What is actually happening is that the water is being retained in the wall, and the lintels deteriorate faster.

Another common problem with the lintels is the relatively recent practice of wrapping the window trim and steel lintels with aluminum cladding when windows are replaced.  The intent is to protect the lintels, but the aluminum wrap cladding actually holds the water in the wall, which accelerates the deteriorioration of the lintel.

These misbegotten repair practices are so ingrained in Chicago construction trades, it has become standard practice to keep applying new mortars over the old mortars until there is a convex bulging mortar joint instead of a nicely struck concave joint. There are some new masons that have labeled this "European Tuckpointing", as if the practice has some centuries old roots going back to the "olde" country. While the new masons understanding of American marketing is admirable, the practice is a disaster for the buildings because the bulging joint has thousands of little ledges and gaps that trap moisture and actually funnel increased amounts of moisture into the wall.

There are a couple simple lessons in all of this.

First, it is not necessary to "protect" the older mortars. If we don't actively abuse our buildings by applying the wrong principles, materials, and methods, they will last. They have withstood thousands of years of use all over the world, and if the building is reasonably maintained, tuckpointing is most likely only necessary every 25-30 years at most. Yes, there might be miscellaneous spot repairs necessary, or the building owner might want to clean the masonry to make it look better, but plainly and simply, the original mortars will function just fine for decades if they are not slathered with Portland cements, or otherwise abused by not maintaining roofing, parapet wall coping tiles or other waterproofing components of the building.

Second, if one is doing repairs to their masonry building, they should be aware that there are vast differences in the mortar, and using the wrong mortar is detrimental to the building. When talking to your repair mason, make sure they understand these things. If they don't, the likelihood is they are going to damage your building, not repair it.

Which finally brings us to tuckpointing.  This is a commonly misused term.

The correct term for this repair work is "repointing", or simply "pointing". What this means to us is even the terms that the new generation of masons not only use the wrong mortars, they don't even use the proper terminology for their work. Call me old fashioned, but if someone doesn't even know the correct terminology for the processes they employ, I tend to be weary of their knowledge and skill for executing the work.

We are blessed with a very unique architecture and building material in this City. If we want our masonry homes to continue on, we must educate ourselves, and then the tradesman that work on our properties. If we don't do these things, we can expect that our homes will fall apart rapidly and have excessive repair costs. It's always cheaper to do things right the first time.

And, a professional and knowledgable home inspector can help in this regard.  Much of my work is consulting, both to home and building owners and to contractors.

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Rainer
316,590
Linda Metallo DiBenardo
RE/MAX Impact, Lockport, Illinois - Lockport, IL

Thanks William, I bookmarked this.

Linda Metallo, Lockport, Il.

Jan 05, 2010 09:09 AM #1
Rainer
14,593
William Decker
Decker Home Services, LLC - Highland Park, IL

My pleasure, Linda.  Feel free to print out and hand around.  Good information is always helpful to the public.

Jan 05, 2010 09:39 AM #2
Rainer
6,612
Barry Adair
ADAIR INSPECTION - Dallas, TX
TREC#4563

Will, nice article, who/what are your sources?

Jan 05, 2010 09:46 AM #3
Rainer
14,593
William Decker
Decker Home Services, LLC - Highland Park, IL

History books, the Portland Cementg Association (I live about 1 mile from their headquarters), some old Masons, the ASTM standards, Architects and my own inspections.

Thanks for keeping me honest, Barry.

Jan 05, 2010 09:52 AM #4
Ambassador
1,336,816
Charles Buell
Charles Buell Inspections Inc. - Seattle, WA
Seattle Home Inspector

Hey Will---did you see my post on the spalling at the brick Fort Jefferson in the Dry Tortugas, Florida?  If you can't find it on my blog I can provide a link if you like.  Some of the most extreme spalling due to rusting iron I have ever seen.

Jan 05, 2010 05:05 PM #5
Anonymous
Linas Dapkus

Good article. All these points were also covered at your recent Masonry Evaluation CE Seminar for Chicago NACHI. Thanks again.

Jan 05, 2010 11:28 PM #6
Rainmaker
179,897
Jack Gilleland
Home Inspection and Investor Services, Clayton - Clayton, OH

Good info Will and as usual well written.  Thanks.

Jan 07, 2010 05:57 AM #7
Rainer
18,257
Gabriel Silverstein
Angelic Real Estate, LLC - New York, NY
SIOR

Does the InterNACHI membership agree with its own general counsel, Joseph Ferry, who said this in response to a discussion on LinkedIn's Notre Dame group relating to an anti-gay cartoon published in the Notre Dame newspaper this past week:

 

 

"Okay, everyone, take a deep cleansing breath and get a grip. It's not like they insulted the Prophet Mohammed, who would be totally down with the sentiment expressed in the cartoon, by the way. 

And gays are not the only population that should take offense at the cartoon. Anyone who has been in a nursing home knows that being in a vegetative state is nothing to be lampooned. 

The suggested "discipline" strikes me as over the top. This is really a very bad joke - and not exactly side-busting, at that - that some post-teen, bereft of the wisdom that age imparts [sometimes] and blissfully unaware of its wider implications passed on for reasons that would elude pretty much the entire constituency that reads these threads. 

Still the offense does call for exemplary consequences. May I suggest removal from the staff of the Observer and a month of dinners in the South Dining Hall?"

 

Ah yes, those gay bashers at Notre Dame - ranked first in The Princeton Review's list of the most unwelcoming campuses for gay and lesbian students - make them eat dining hall food as punishment, apparently not because they got caught publishing gay bashing cartoons, but because they weren't "exactly side-busting", though maybe the key insight here is that apparently he believes it would have been okay from a Moslem point of view as well and between the Christians and the Moslems he feels good that he's got a pretty strong caucus of multiple religions behind it, so I guess in that light it must not be that bad then in his eyes.

He posted this specifically identifying himself as the General Counsel of InterNACHI, so apparently in his capacity as such this is his public platform.  

I certainly don't think I plan on ever using an InterNACHI inspector as long as bigotry is okay as a matter of public statements of its own head legal counsel.  I suggest anyone that doesn't support gay bashing and other bigotry should seriously rethink who they work with for home inspections, especially for any LGBT clientelle, who I am quite certain would not appreciate paying someone that pays dues to support this guy's salary.  If InterNACHI members don't agree with this I suggest a rather rapid response to the InterNACHI board expressing that perhaps this isn't a broadly supported position by its membership.

 

Jan 16, 2010 01:36 PM #8
Rainer
14,593
William Decker
Decker Home Services, LLC - Highland Park, IL

Mr. Ferry's opinions are his own.  I have a large clientelle of GLBT Realtors and clients who I work with and hwo have never expressed any difficulty with me.  Ones sexual orientation has nothing to do with the condition of the property that intend to buy.

I will say, however, that this post on a thread that has nothing to do with Mr. Ferry, or his comments, is rude and typical of those who desire to bully.  You, Mr. Silverstein, have the right to comment on his comments in that thread and blog.  For you to do so on this thread and blog is rude and silly.  It also displays you stooping to his level.

Be well. 

Jan 17, 2010 01:21 AM #9
Anonymous
KC

Thanks for this info. I just found it through google. It's great to know that not only is my apartment complex's maintenance extremely loud and annoying, it's also useless and destructive. Great. 

 

Also, if you have homophobes working for you, just fire them.

Oct 09, 2010 03:37 AM #10
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