Ridge tile access on a hip roof

[vernerbongo2]

Alright lads/ladettes

Ridge tiles are randomly coming off our hipped roof in windy conditions due to rusty screws that are 30+ years old.
My da wants the blown off tile fixed but I want them all rescrewed.

What's the easiest way to do this, the ground around the house is at different levels and slopes etc.
https://drive.google.com/file/d/0Bx34Ykhd2y7EeVRQTllWMFg5blE/view?usp=drivesdk
A building friend says tie a roof ladder at both ends at the same angle as the ridge, sounds risky to me.

 

[noseall]

Scaffold usually works for us.

 

[vinn]

OP,
There's no easy way - best done by a roofer.

I can see a missing hip tile - is that what you are referring to?
A secure tower, and a tied-in (to the tower) roof ladder would get you to the hip(s) or ridge.
Whatever, dont walk on the slates or allow anyone else to walk on them.

AAMOI:
I can also see a faint dark smudge on the chimney breast dash - if you've not had your flues swept (including the redundant flues) maybe do it now.
Where the soffit and gutter meet the inside corner (near a flat roof?) there are water stains - perhaps from overflow?

 

[vernerbongo2]

Thanks I'll get someone to do it and also look at the other suggestions you've made.