Can anyone give me some help? I'm a the owner of a 15 yr old home in Calif. The other night I heard a loud SNAP from outside. Next day I walk out onto the back patio and see some concrete or stucco chunks on he patio. Following them to the source, I see a stranded steel cable sticking about 3 inches out of the slab! I'm guessing the post tension cable anchor broke, but what should I do? Will this cause any foundation problems?
Thanks or any ideas.

We in the Northeast are totally unfamiliar with post-tensioned construction in residential work. Perhaps someone from a region where this is common will respond to this question.

I to Just bought a post tension home also in California(Ryland)they only seem to be ddoing them here at this time. I pray to God that I don't have any of the same parblems , any way I think that you should find all of your paper work and go back on the builder ASAP Don't take No for an answer about them fixing it even if you wind up in court.

God Bless

i have worked on job sites where post tension of cables in slabs are used for structural strength. If you do not know the contractor that built the home I would recommend a structural engineer take a look and suggest a remedy. The steel cables are under quite a bit of tension. This is something that you don't want to put off. you might need to provide some temporary support. If you post a picture that maybe helpful.

I live in Oklahoma, and we use post tensioned cables in locations where there is a possibility of the ground shifting due to weather conditions. The cables keep the concrete from shifting or seperating if it cracks. It does not keep it from cracking, only from changing heights or seperating apart. I would say there is no problem as long as it did not bust the concrete when it snapped. There are probably cables every three or four feet in a grid.

Good Morning, Flyer,
As a high end custom design/build firm in Texas we have seen many post-tensioned slabs over the years.
You say a 3" piece of tension cable end was "sticking out of the slab", you don't mention if this was the patio slab, or the slab to the home.
I am going to assume the patio--reason being, after fifteen years (after the concrete completely cured in the original pour) the post-tensioned cables in the home's slab are no longer are pressure within the monolith pour of the slab to the home, which, if built to code is thicker than the patio slab. Soil shifts and aggravating weather conditions--lots of rain, for example, could cause a cable to break thru the thinner slab of the patio.
This also could be due to too low a PSI rating on the concrete used for the pour, but after 15 years, I feel that problems due to this would have shown up sooner.
You also don't mention being the original buyer of the home, or not--most builders, at least in our area, our company included, are required to offer a 2/10 warranty, so after 15 years, pursuing that avenue is probably not something to waste time on. However, I agree with DaveC, do have a structural engineer take a look at the problem if you are uncomfortable with progressing damage and personal safety, and depending on cause, might have a homeowners insurance claim for repairs.

Try the folks at Exponent (or another similar firm), an investigative engineering firm. They look at these situations every day and are known by your insurance company, which you will have to contact anyway if this is a major issue (i.e., the cable is part of the house structural system as opposed the patio slab). Because of their experience with insurance issues in CA, they can advise you on the types of causes that are/are not covered, which the rest of us cannot since CA is so unique....


You did not mention your location, otherwise I would give you a contact at the nearest office. Full disclosure...I used to work for Exponent. However, choose any firm you like to assist you; my main message is to spend a little money now--with a firm that is familiar to and understands the CA insurance world--so you know (1) if this is a serious issue and (2) if your insurance company might cover the repairs.

My wife (not an engineer) was an employee of Exponent, back when they were Failure Analysis Associates. As a retired firefighter, I'm familiar with their work in failure investigations in Kansas City, NYC, and other major collapses, but my wife said that they also do smaller investigations, recreations, and analysis. It is a good, well rounded engineering/analysis/investigative firm. They would also be very aware of similar failures, especially if there is a potential for catastrophic collapse.

That being said, my knowledge of pre- and post-tensioned concrete is limited to structural collapse as it relates to firefighting, and my gut reaction is to say "Get a Structural Engineer NOW!", especially if the cable is related to your foundation or any support beam.

ANY failure needs to be checked; it may be innocuous, but I'd certainly rather pay to be told not to worry, than take a chance on something coming down around my ears during the next seismic activity (or even with a heavy truck driving past.)

Hi, as a Professional Inspector in Texas I see a few broken cables each year. This is usually not a major issue, and generally caused by improper installation. The solution most of the time is to remove the broken cable, install a new one (this is why they have the pvc sleeve), and re-tension; then repair the broken concrete. You may want to look around the outside edge of the foundation to see if you have any exposed cables. If so, they should be cleaned of corrosion and grouted over to prevent air contact. Corrosion causes most of the failures. Any foundation repair company and most slab concrete contractors should be able to handle this, sadly, it is not a DIY project. Best wishes.

As Inspector noted previously you need to contact a concrete contractor that deels in post tensioned concrete. I too am a professional Inspector in the SF area. The info he gave you was right on and after 15 years this is not a defect but most likely caused by corosion at the wedges that hold the tendon in the anchor. These tendons are under 33,000 pounds of tension so you don't want to handle this yourself. In my field of work I personally observe and report on repairs of tendons in both new and older homes. The loss of one tendon will most likley not result in any structural damage to your home. But you need to have repairs made soon. Good luck. Litnlennie

I was doing a little research on post tension cables breaking as ours snapped a couple of years ago. I see that you are an inspector and thought you might be a great person to ask this. We are getting our house ready to sell and I wanted to know if that is something I need to disclose on the seller disclosure form. The foundation was under warranty and was repaired (with an engineers approval). My concern is, the home builders rep actually told me there was no need to disclose the information as there was really nothing wrong with the slab itself.
I would appreciate your input!
Thanks

quote:

Originally posted by Inspector:
Hi, as a Professional Inspector in Texas I see a few broken cables each year. This is usually not a major issue, and generally caused by improper installation. The solution most of the time is to remove the broken cable, install a new one (this is why they have the pvc sleeve), and re-tension; then repair the broken concrete. You may want to look around the outside edge of the foundation to see if you have any exposed cables. If so, they should be cleaned of corrosion and grouted over to prevent air contact. Corrosion causes most of the failures. Any foundation repair company and most slab concrete contractors should be able to handle this, sadly, it is not a DIY project. Best wishes.

You must always disclose any past structural knowlage that you have on your home your selling. The Home Builders rep is wrong.
If folks that purchase your home find out even after the sale they can find you and sue you for any hidden damages that they find.
Get your lawyers advice on this. But its best to disclose everything up front.