I've drilled through electric cable in random spot! Mates a plumber and he told me he went to a customers house to find he had just installed a new oak floor using his nail gun, forgetting he had under floor heating!
One of my ex-colleagues did something similar. We'd cut out a run in the floorboards to allow the sparks and data guys to run two armoured cables and a shed load of CAT6 data cables (on opposite sides of the "trench" - listed building). It was left with the cut-out short pieces just lightly pinned back in place for several months. Come time for the new plywood sub floor to be fitted and the new guy was told to go and fix down the old boards properly. He did so, using 4 x 70mm screws. Every screw missed the cables - except the one which neatly pierced the uppermost armoured cable. I believe the testing and repair cost for that was somewhere in the region of £3k...It could be one post wonder or a forum expert, hasn't everyone done it
No you don't!You do it only once