How to fix apron flashing

[Niftythrifty]

I have damp on the wall in line with the top of the chase for the flashing in the pictures below. I can see some hairline black lines in the render above what looks like sealant in the chase.

I think the water is probably getting in through the render above but am also concerned the overlap on the drop isn't sufficient. This wall gets hammered by the wind and rain - I live on top of a hill and this wall faces SW.

My plan is to chip off some of the render and replace the lead sealant. The job is 8 years old but we have had a patch of damp inside through the winter months. Wall is single skin.

I was wondering if I also need to seal the gap under the overhang of the drop to the bottom section of lead. The top piece of lead is 9cm drop from the chase but only overlaps the bottom section by 4cm. Therefore I suspect some water is also being driven up. That would make sense with it being a winter problem.

My first post here so welcome all advice. I'll need to get scaffolding to do the full run so want to know what the best solution will be when I'm up there.

 

[datarebal]

Flashing is faulty

 

[BethesdaSlater]

There are horizontal laps at the top of the aprons, which will allow water ingress.
You'll need to remove the aprons, install a fillet so the pitch of the roof is extended to the wall and replace the aprons again, which will then have the required fall .

 

[catlad]

Yep. that's where I would start. Hopefully if you bend the lead tabs back the lead aprons should slide out.