ok all our engineers are trained not to drill from outside in,simply because you can not check with any type of detector through a wall that is between 12in ans 3 ft thick!..most customers want the coax coming through the wall where all the face plates are i;e existing aerial socket and power...
so how do we test from outside for cables or pipe work,,i have been in the satellite buisness for 20 years ,and now am a team manager for one of the largest satellite /aerial company in the uk .and if one of our engineers drilled frrom outside in they would be in trouble if they hit a cable or pipe