How do I reseat lead flashing

[laycockcider]

What is the best way to re affix lead flashing to the flat roof to make it watertight again?

 

[datarebal]

can you post another picture from a few metres away?
if it just a cover flashing it should not need sealing. there should be a felt upstand stopping water entering..
I can see a small patch under the lead?

 

[Doggit]

You want a rounded block of wood, and a hammer. You can't use a hammer direct to the flashing, as it makes the lead brittle, so you hold the wood against the lead, and tap the wood to get it back into position. Start at the top of the flashing, and work downwards to get it back into position.

This is what you'd normally use though.

 

[vinn]

You dont need a hammer period - any hand held off-cut of 2" x 4" can be used to dress down or push back the lead flashing.
A hammer might be used to re-set any lead wedges.
If you were to use a bossing tool then the last tool you would use would be a boxwood dresser - the dresser is for sheet lead/metal work.

OP,
Why not, in addition to the context photo suggested above, post a pic showing the back of the abutment, and a pic with the cover flashing lifted - showing how the upstand is waterproofing?
You say that you want to"make it watertight again" - implying that its now leaking?

The lead cover flashing should have been set a little higher up the abutment & should not touch the roof plane itself but merely cover the upstand.

The flat roof felt has been previously patched, & appears to be lifting and failing.
What your pic shows is a very amateurish bodge at flat roof detailing.

 

[chappers]

unless it's leaking you don't really need to do anything here. Not the best work in the world but should be OK. Maybe just lift it up and make sure the felt is turned up the abutment as datarebal describes