need some advice on fixings, I plan to run a 4 foot high panel fence on top of a wall approx 14 panels long,using bolt down fittings, the trouble is on top of the wall the brick work is some sort of engineering brick on edge with ten holes in each, shall I drill through the top course to get a good fixing in the brick below, I reckon to need bolts at least 160mm long, any ideas appreciated,,