Hi, the helipad I posted here the one with led lights and strobe lights has holes in the whole pad and is also designed to get rid of prop wash
and as mentioned works realy well the pad is also raised on 5" legs so the prop wash can flow away from underneath.
I like the idea of the North pointing arrow I make a arrow cut out of ply wood painted Red and always point it to the helipad and into the
direction of the wind.
Just some further ideas.
Cheers, JV