sjvcon Report post Posted September 30, 2016 There are locators down there who can image the cables. They should get you "safe zones" to go in. With a house the cables are spaced pretty wide so once imaged you "should be" ok. 1 Share this post Link to post Share on other sites
PRDATR Report post Posted September 30, 2016 Because this is a slab on grade you cannot x-ray it, you will need to GPR to locate PT cables. Your slab is most likely 4" thick, maybe thicker in some areas and your cables are centered in the slab. If you are looking for safety (doesn't fall over on your dog) and not for enough capacity to resist a burglar pushing it over, then you only need to install a drop in anchor that is 1/2" deep, a 3/8" dia. x 1/2" deep should give you plenty of capacity to hold it in place. Put more than one if you want I thought that residential post tension slabs were 8" with cables spaced 48". 1 Share this post Link to post Share on other sites
5guyshunting Report post Posted September 30, 2016 Because this is a slab on grade you cannot x-ray it, you will need to GPR to locate PT cables. Your slab is most likely 4" thick, maybe thicker in some areas and your cables are centered in the slab. If you are looking for safety (doesn't fall over on your dog) and not for enough capacity to resist a burglar pushing it over, then you only need to install a drop in anchor that is 1/2" deep, a 3/8" dia. x 1/2" deep should give you plenty of capacity to hold it in place. Put more than one if you want I thought that residential post tension slabs were 8" with cables spaced 48". YEP! Share this post Link to post Share on other sites
Ed67 Report post Posted September 30, 2016 I used 3 1/2"-1"!wedge bolts to anchor mine and didn't even check..😁 I won't be home for a while and now I'm worried. Oh well I used a hammer drill and didn't feel any unusual resistance. 1 Share this post Link to post Share on other sites
PelaPapas Report post Posted September 30, 2016 Man, let's see what I do. I really want to get this bolted down ASAP. Share this post Link to post Share on other sites
longshooter Report post Posted September 30, 2016 when you do drill your holes I recommend using a Simpson titen bolt with no more than a 3" embedment over a red head or aka anchor bolt. You get much more bite from a titen and with a impact you can unscrew a titen unlike a anchor bolt that wedges itself. You can get Titens at whitecap or Carlson construction supply. My crews install anchor bolts and or Titens on dozen of slabs every week as framers for plate beaks on exterior walls and interior walls for shear transfer walls and for hold downs. They occasionally hit a cable when they over drill a hole. It's not as big of a deal as everyone says. I also recommend having a concrete guy come out and they can mark and tell you were the cables are at. I see it all the time when they have to install missed conduit or plumbing at kitchen islands etc. Share this post Link to post Share on other sites
5guyshunting Report post Posted September 30, 2016 If it was my deal, I would use 1/2" drop in anchors. Use a 5/8 roto- hammer bit and drill down 2 1/4" to 2 3/8" , put the anchor in and set it. The anchors are only 2" long, get some 1/2" diameter bolts and tighten down. I use one of these anchors to mount a 150lb core drill and stand to a wall. The post tension cables should be deeper in the slab. Just my .02 cents. Ps. I have been cutting and demoing concrete for 22 years. 1 Share this post Link to post Share on other sites
HuntHarder Report post Posted October 1, 2016 The cables do NOT explode when hit them with a drill. Just use a smaller hammer drill, and you will feel the drill bit hit something IF in the unlikely chance you drill into to one. You can go on the side of your house and see where they patch the holes where the cables are and get an idea of the spacing of them. Just my $.02 Share this post Link to post Share on other sites
Guest oneshot Report post Posted October 1, 2016 I'm sure there are some glues that would do the job, maybe even better then bolts, without the worry/hassle of the cables being in play... What if after all the x-ray'ing/expense you find a cable running right where you want to put the safe??? Share this post Link to post Share on other sites
hoghntr Report post Posted October 2, 2016 I used 3 1/2"-1"!wedge bolts to anchor mine and didn't even check..😁 I won't be home for a while and now I'm worried. Oh well I used a hammer drill and didn't feel any unusual resistance. House didn't slide off a mountain or anything like that? Share this post Link to post Share on other sites
Hoss50 Report post Posted October 2, 2016 Titan bolts are where it is at. 1/2" x 3" long and your pretty stout. I would just drill it honestly. It is doubtful you will hit a cable. 2 Share this post Link to post Share on other sites