We will all soon see that the easiest way to get out of this conundrum may be to add siding of some sort over split face as you will only be able to apply so many coats of elastomeric finish or sealer before you give up on guessing where water is getting in. Just my .02
The previous respondent did you and all Chicago consumers a favor by alluding to Steve Hier (Miller Hier) to inspect split faced block. In a word split faced block "sucks." I tell my buying clients that it is essentially a rocky sponge, soaking up precipitation unless it has been properly treated with a water repellent that lasts anywhere from three to ten years to keep water out (and to have little ropy stubs (called wicks or weeps) extending from the block to allow water within to make its way out).
Unfortunately, most condo associations being made up of new or first time buyers don't have a checklist regarding association maintenance. One of the unfortunate things that can happen when split faced block is untreated is that it gets wet, and when it gets wet there is a possibility of damage on the other side of the block (the condo's inner wall). There is also the risk of mold. But look, I don't want to be too dire - if this stuff is maintained properly, you don't have to worry about being a nightmare anecdote that friends tell friends about some split faced block building in the city.
By the way, having worked with Steve Hier to inspect the bulk of my buying clients' places I have heard nightmare stories. The reason builders choose block is that it is considerably less expensive than an all-masonry building. And most consumers aren't educated as to the value of brick and the risk of block.
Knowing the value of brick or the aesthetics of frame, I would not buy a home with split faced block.
Good luck with the purchase process.
The Real Estate Lounge Chicago
Hope that helps.
Other new developments include vented termination bar for the roof membrane, elastomeric paint sealing, vented copings (the 21st century version of clay coping tiles. Go figure!) and professional home inspectors who are really building scientists and can properly evaluate the buildings as a whole.
The next step in this problem is structural collapse of the trusses. See here: http://deckerhomeservices.com/Split_faced_block_update.htm
Hope this helps;
Now to reality, they are typically garbage buildings and most won't be standing in the next 30-40 years. I've spoken with many professionals who feel the same way.
It's the next mortgage crisis that will come down the line for owners of such buildings. They'll have a mortgage on a building that is ready for demolition.
Now to what will probably get me kicked off of here. CMU is one of the great ethical crimes committed by developers and real estate agents against consumers. In 11 years I have yet to hear a single developer or real estate agent explain to buyers that CMU buildings need ongoing maintenance. I have never seen a document given to a buyer that explains the ongoing maintenance needs. Whenever I inspect a CMU building I always ask the buyers, 'has your agent or the developer given you any documentation or talked with you about maintenance?' The answer is always NO.
Agents have consistently made CMU new construction out to be such a great thing. I realize you don't get paid unless the deal closes but there should be limitations on the amount of BS someone is willing to shovel onto the consumer.
Your question of whether it is a reasonable option if properly installed and cared for is larger than you may realize.
Let's look at the other CMU myth everyone is spouting out now to cover their butts - 'it just needs proper maintenance'. On paper that is true. Unfortunately many are using that statement as a scapegoat tactic to put the building failure blame back onto the consumer. 'Mr. Condo owner or Condo Association its YOUR fault the building leaks, YOU didn't maintain it'. Of course no one ever told the buyers they needed to maintain a brand new building. Of course liability isn't why the developer let the LLC lapse as soon as possible after the project was done.
The terrible reality of the situation is that many of the buildings are built so wrong from the start that maintenance barely works if at all. The condo owners can do all the maintenance they want and it may not help. Why? Because In order for the water repellants to work properly the building has to be built right from the start. I've inspected CMU while they were under construction and rarely found crews doing it right. There are a lot of inherent defects built into many of these buildings. Poor workmanship, lack of knowledge about materials, correct procedures and cost cutting in the name of profit.
Epoxy coatings are likely to be the product of choice in the future. I've spoken with Mason's who install water repellants and all have stated coatings last 1-3 years regardless of what the label may claim.
Buy vintage, stay away from CMU. It can be done right but rarely is.
There are a variety of reasons that split face block is not performing and understanding how a particular building was built is very important. In cavity wall construction you are relying upon a drainage plane and several VITAL flashing and moisture moving materials to be properly installed (if at all present) as well as functioning. Too often we come across buildings with poorly installed flashings, painted or caulked over weep holes, overly projected door and window frames, missing capstone or parapet flashings, etc. Yet some buildings with some of these missing details have not had any moisture issues.
Recent studies are moving away from spray applications for single wythe concrete block construction sealing to high-build, elastomeric coatings which hold up better and reduce moisture "loading" of porous block. If you do a search for "Masonry Institute BC PDF 2.7.2" you will see what one of the governing bodies is leaning towards. Good luck...