Thanks all for your advice
Still not in a position to be able to test - freezing fog yesterday, cold again I think overnight which will no doubt cause some condensation on the roof making it difficult to test.
I have noticed a board up of a roofer down the road who also deals with brick cleaning which ideally I would want done to bring back to its former condition the best it can so this might be a good route to go down.
Armed with the information/advice on here so far, I think I'm at a much stronger position now so I will try and get him down to have a look and quote on the findings.
I wonder if it is also worth again based on a comment on here, getting a quote on adding a secondary drain near the camera/on the other wall. The one house that has two drains is in this manner - the existing corner one and then opposite side to the right of where my camera is.
Will report back on here what the findings are and go from there
I think either way whatever the issue is, it is not something I would have the skills to undertake
@jeds I think you (and
@wessex101 ) have most likely hit the nail on the head there. I am more than 95% sure the video I had take in the heavy rain demonstrated exactly this.. I just did not think it would be any different to the wall being hit by rain but clearly this is an issue
Speaking to the two neighbours who have cladding around their brickwork, they've both said their cladding is turning a bit green and they too have water pooling so chances are we all have the same issue