I am installing a floating hardwood floor on a concrete slab. I am concerned about hitting plumbing by drilling 1.25 deep holes to install plugs to attach my reducers. Is plumbing installed under the slab or in the slab? Is there a way to find the pipes in the slab? Its unfortunate that I have to install a reducing strip between where the water pipe enters the house and the hot water heater/laundry room. Any help would be appreciated. Steve