Drilling Post-tensioned slabs - liability

[usuallycivil]

We are a small general civil & structural design firm. We frequently receive requests to design minor modifications to all sorts of building types. We have typically shied away from jobs that involve any type of work on PT slabs. The thought being, that if some mishap should occur if a tendon is accidentally cut, and (God forbid) someone is hurt, we would get sued regardless of how many disclaimers we had on the plans.

Now with work being so hard to come by, we are re-thinking this policy. Question is, has anyone else come to terms with this issue? What kind of disclaimers do you use? Require the contractor to do X-rays? Any discussions with your insurance agent on the issue?

Thanks for any suggestions offered.

 

[JedClampett]

I think you should use the industry standard of care (review drawings to avoid tendons, X-ray, shallow holes as possible, etc.) and keep your insurance up to date.
My opinion (more important, my boss's opinion) is that you should never be so scared of being sued to change your procedures.

 

[B16A2]

I would hire someone who has a bit more experience in and feels more comfortable working with PT.

 

[apsix]

From this thread;

http://www.eng-tips.com/viewthread.cfm?qid=222517&page=2

"have a local testing lab come out and use a pachometer. This is a simple machine that will locate rebar and cables. X-rays can also be done but they are typically expensive and can be cumbersome tests. A pachometer can be rented for probably 50 bucks for a couple of hours. Remember that these things have a little inherent inaccuracy so leave a few inches clear around things. Also know that if there is conduit on the underside of the slab it will pick that up as well"

 

[Rjeffery]

A Pachometer is a great tool for general location of reinforcing steel. Its limitation is that it has no printed/paper/electronic record. Some skill is needed as well. Lately, ground penetrating RADAR (GPR) is being employed to locate and record the location of both steel and PT cables. I would rather have documentation from GPR than a +/- 2-inch guess with a pachometer...

The best way to test something is to squeeze it, slowly, until it breaks!

 

[nuche1973]

Got into a big discussion with a contractor over an apartment complex that had the same type of slab system. We ended up having to consult with a company that specalizes in this type of work. Also found out that certain companies in the powder-accuated business recommended not using their products for P-T slabs.

 

[usuallycivil]

Thanks to everyone for your comments.