A.Bob Kovacs, president of Constructive Solutions in Iselin, N.J., and moderator of the estimating forum at jlconline.com, responds: I installed dozens of post-tensioned slabs in homes in Las Vegas, and just recently finished a 10,000-cubic-yard post-tensioned parking garage. The cables are tensioned to approximately 30,000 pounds, and if you cut one the wrong way, the force can easily kill you. I've seen cut cables rip out of slabs on several occasions. One ripped open a 10-foot-long strip of slab and sliced through a shear wall. Another slammed into a dishwasher 5 feet from the hole and sliced it in half. In both cases, the geniuses who caused the damage were lucky enough to avoid harm.
In most cases, the cables can be destressed by a post-tension contractor. It's not an easy task, especially if the location of the cables isn't easy to establish, but it's the only way to proceed unless you plan to do all the demo from the cab of a very large excavator with a hydraulic hammer and can keep everyone far from the area. I wouldn't...
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