| Author |
Message |
Jerome J. Lazar, RA, CCS, CSI
Senior Member
Username: lazarcitec
Post Number: 1921
Registered: 05-2003
| | Posted on Tuesday, August 28, 2018 - 05:29 pm: |    |
This question is actually for Mark Gilligan, though all are welcome to respond. A client asked about the possible failure of the Concrete structure in a 40 year old concrete condo building in So FL. Their client is hearing noise coming from the concrete floors, sounding like cracking? Should they head for the hills or sell their condo to the highest bidder while they can? |
David G. Axt, CCS, CSI ,SCIP
Senior Member
Username: david_axt
Post Number: 1713
Registered: 03-2002
| | Posted on Tuesday, August 28, 2018 - 06:24 pm: | |
Nothing lasts forever and PT slabs do sometimes fail. A few years ago in Seattle a 9 year-old PT slab building was torn down due to construction defects.
https://www.treehugger.com/sustainable-product-design/seattle-high-rise-being-demolished-its-all-of-nine-years-old.html
If the owner is really concerned then they should hire a professional structural engineer to inspect the building.
David G. Axt, CCS, CSI, SCIP
Specifications Consultant
Axt Consulting LLC |
Jerome J. Lazar, RA, CCS, CSI
Senior Member
Username: lazarcitec
Post Number: 1922
Registered: 05-2003
| | Posted on Tuesday, August 28, 2018 - 07:32 pm: | |
Thanks David, cool to read about the project in Seattle. Being a condo, there are multiple owners, one owner can not do much unless the others have similar concerns.
I wrote specs on a high end condo in Naples 12 years ago, a year after construction one home owner developed a chronic cough, she blamed her condo, she had it tested and they found high levels of radon, the other unit owners tested their units as well, but only the one unit had the high levels. I was not privy to the suit, but the developer purchased her unit for a huge premium. The unit stood vacant for several years. I never heard about any remediation, the original developer went out of business, it was a great location, I expect it was resold. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 863
Registered: 10-2007
| | Posted on Wednesday, August 29, 2018 - 01:46 am: | |
Calm down and hire a structural engineer to investigate the problem. Find one who is familiar with post tension design.
I will not say that there are not problems but there can be a number of causes for the noise that are not the cause of structural distress.
If the noise were to be from structural distress I would expect to see signs of significant floor deflection.
A definitive investigation might require exposing the anchorages and some testing. Not a trivial effort. Still start with an initial investigation.
Are other residents reporting similar concerns? |
Jerome J. Lazar, RA, CCS, CSI
Senior Member
Username: lazarcitec
Post Number: 1923
Registered: 05-2003
| | Posted on Wednesday, August 29, 2018 - 02:19 am: | |
Calm Down? You must be a mind reader Mark, I am upset but not because of PT Conc, I don't know if there are other residents with similar concerns, I decided to post here because this forum has some of the most educated and yes the smartest architectural (and engineering) professionals on the planet as participants, yes that includes you Ron, Ken, Wayne, Mark, John, Peter, Lynn, Anne, Robin, Davids, and so many more. Where else would I post, on Facebook, don't think so, on linkedin, not me, 4specs gets my vote.
Now back to why I need to calm down, tonight is an example why I am glad I am not practicing Architecture anymore, I have learned that Architects can be as distrustful as any other construction professional. I will make this brief, a former Architect client reached out to me a few months ago for a favor, baited me with the old the next time I need specs of course I will call you line. Well this evening I found out that their next mixed use tower which I thought was to be my job has specs from someone else, its upsetting mostly because its the kind of job that is in my wheelhouse and would give me the opportunity to rekindle relationships with this firm. It is especially hurtful because this firm stopped preparing specs on their projects for awhile but now they are doing so. Its tough being a specifier in So Florida where specs are not considered necessary on private sector work, every job is a fight, getting paid and being paid what the job is worth is not easy.
If I had the opportunity to start over, it would not be as a specifier in So FL thats for sure. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 1172
Registered: 12-2006
| | Posted on Wednesday, August 29, 2018 - 09:42 am: | |
Interesting. Back in the 80's I was called in as a waterproofing consultant on a leaky hi-rise luxury condo in downtown Washington, DC that had been built in the 60's. The PT decks extended outside the building envelope to form balconies around each level. Very heavy precast concrete 'railings' ringed the balconies. Many of the residents had opted to put outdoor carpeting on top of the concrete balcony surfaces; the carpet was very effective at holding moisture against the concrete. Gaps had started forming between the concrete and framing where the glass exterior walls enclosed the interior spaces. The condo association wanted to know if I could suggest a good sealant to reseal the base of the framing. I called in the structural engineer who designed the building who raised concerns about the deflection.
After removing a number of the precast 'railings' it turned out the grout had eroded, the anchors had rusted away, and many of the tendons had disintegrated. Many millions of dollars later the tendons, anchors, and grout were replaced and the building still stands. Oh, and they did reseal the framing and no longer permit carpeting on the balconies though we never actually proved that was what caused the problem.
Still one of the most expensive places to live in DC. I haven't been invited back. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 864
Registered: 10-2007
| | Posted on Wednesday, August 29, 2018 - 12:11 pm: | |
Yes corrosion is the source of a lot of problems with PT structures and should be considered but it is not clear that the reported symptoms are a result of that problem.
If it is a problem it is more likely something that the home owners association would be responsible for.
While the idea of selling the unit to somebody ignorant of the problem may be appealing, the current owners might find that they have an obligation to report the problem to potential buyers. |
Jerome J. Lazar, RA, CCS, CSI
Senior Member
Username: lazarcitec
Post Number: 1924
Registered: 05-2003
| | Posted on Wednesday, August 29, 2018 - 12:35 pm: | |
Mark I never said the homeowners were selling their unit to pass the buck, I presented an example of an entirely different situation where the problem was significant for one home owner but maybe not the next. I've never owned a condo, I've never experienced that form of ownership, I own a single family home in a PUD, I don't even want to discuss the problems I am having with the HOA, its mot pretty, I can't imagine how much worse it would be if I lived in a condo.
On this forum I was seeking your advice because in the past I have learned from your structural knowledge, its sad that I reached out to a few PEs I work with and all are too busy to answer or decline to do so. Perhaps they are all too busy preparing for Labor Day. Or maybe I hit a sore spot? |
Jerome J. Lazar, RA, CCS, CSI
Senior Member
Username: lazarcitec
Post Number: 1925
Registered: 05-2003
| | Posted on Wednesday, August 29, 2018 - 01:04 pm: | |
Ken, 12 years ago I wrote up a list of items that should not be installed in condos in So FL, outdoor carpet on balconies was in the top five, as was vinyl wall covering or epoxy paint on the inside face of an exterior wall. The list circulated to condo developers, many of whom added the list to their condo docs.
Wayne, Dr Joe has a list of top 10 errors Northern Architect make in Florida. I believe he dedicated it to his wife. I could not find Dr Joe's list.
Ken, tere is an old story that back in the 80's contractors used beach sand for their concrete mixes and there were many balconies that failed over time, built on Miami Beach, massive corrosion even without the outdoor carpeting to retain moisture. I confirmed this by performing a quick search, http://www.ccfj.net/condoartbalcony.htm |
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