Retro-fitting dry verge on slate roof

My slate roof is bedded onto mortar as shown. Its failed in many places, though this bit is not bad (yet)

I was thinking of some sort of retro-fitted dry verge as an alternative, as it could be a DIY job from a ladder (?) rather than scaffold (tower) for removing and replacing mortar. With no barge boards (its rendered, as you can see) I have no easy way of fixing, which seems to make life harder.

A. Are there reliable systems for doing what I want?

B. Is it a DIY job or really a skilled job best left to a roofer?

C. Would it be able to withstand the wind (we live by the sea)?

D. Is re-doing the mortar the best way at the end of the day?

Plastic and slate roofs don't go together in my opinion so D.

Decided after all to get quotes for re-roof the whole lot. Kills several birds with one stone: quite a few dodgy-looking ridges; no roof felt at the moment; no capping on cavities so wind coming out of every plug socket and floorboard; easier access to tight loft areas so I can add a load of insulation; access to chimney stacks so I can paint the render.

I have no clue what it might cost, though!

WabbitPoo said:

Decided after all to get quotes for re-roof the whole lot. Kills several birds with one stone: quite a few dodgy-looking ridges; no roof felt at the moment; no capping on cavities so wind coming out of every plug socket and floorboard; easier access to tight loft areas so I can add a load of insulation; access to chimney stacks so I can paint the render.

I have no clue what it might cost, though!

Click to expand...

Be prepared for thousands

lol I am. though whether its 5K or 25K I have no real feel. I won't tell the roofers that!