Don't ever depend on mines to do the killing for you, mines are for severely damaging the hotwire and making an audio cue to find the hotwires location. Mines are ineffective if 2 enemys hit your building at the same time, the first one will clear all of the mines.Unrelated but.. last night I had the entire base mined perfectly, then someone changed to hotwire and started laying mines in the barracks entrance, or maybe I should say "layering" mines cause he put about 10 on top of each other. I screamed and screamed at him to no avail, then another guy started laying them at the gate entrance (the map was Walls). So besides two idiots who didn't know how to lay mines, the mines that they DID lay were disappearing almost instantly as the other guy would lay more mines. Finally the one in the barracks said "SOMEONE HAS TO LAY MORE MINES I CANT LAY ANYMORE"
I then left.