How to repair the black strip on top of the ground floor windows

[ChloeRadshaw1]

I have attached pictures of the area I mean. There is a black strip on top of the ground floor windows which is worn very badly. Does this need replacing or should I paint it with Bitumen style paint?

Is this like a black felt band?

 

[misterhelpful]

It looks like lead flashing to me (or possibly a lead type flashing tape).
If it's lead and not leaking then there is no need to replace it - you can carefully re-dress the lead (bend into shape) to some extent but, if it's old, doing so could cause it to split. It looks like it has already been painted with a bitumen type paint, which is ok to use again but may need repainting every few years to keep it looking neat. You could use something like Bedec Multi-Surface Paint on it instead, which is good for this type of thing and pretty cheap too. (It was available from Toolstation the last time I looked.)
You can use the same paint for flashing tape but that is far easier and cheaper to replace than real lead so, if this is what you have, I would opt to replace it. At a pinch, you could even apply new flashing tape directly over lead to tidy it up a bit.
Whatever you do, make sure you remove as much of the flaking paint as possible first.

http://www.toolstation.com/search?searchstr=bedec