S
SRE
We're in a national park too, on slate roofs - agree with you about the tiled bungalows, urban installers don't know they're born ;-). Our roofer just takes the slate out fixes the hook and flashes it all back in with lead. None of it a problem just more time consuming and a bit of extra cost for lead and replacement slates. The only problem we've had was with cambrian slate which gave us problems with the hooks and flashing it back in. I wouldn't expect you to be having problems with leaking after such a short period, it's after a few years of the slate moving with the wind that the leaks wil appear and need to be resolved. None of our customers would let us near their homes if we were drilling through the slate.