locating center grade beams

huangyhg

locating center grade beams
does anyone have a solution for finding the center grade beams under a slab house quickly and with a tool that doesnt cost more than a couple of thousand dollars. also that is nondestructive. ground penetrating radar systems start around twenty thousand which is too expensive. usually one can guess where they should have been placed, but this is not always the case. a company called olsen makes a cement thickness tester that uses sound vibrations but will not work through the carpet or tile and various floorings. does anyone have an idea how i might find them quickly while inside the house whith out using the plans? thank you
you could find someone with gpr and pay them to do it for you.  it'll cost much less than $20k...
your right swearingen, but i do this quite often and would like to come up with a device that is affordable and rapid. a wall stud finder uses some type of a signal to see the wood behind the sheetrock, and a rebar finder uses probably magnetics, does any one have an idea or solution to finding the cement beam? i was hoping a rebar finder could maybe detect the presence of more rebar at a beams location, not so. maybe some type of a sonar device, that senses the soil being just 6 inches away or at 20 inches if under the beam. i have not been able to find such an instrument.