chimney leak or brick saturation?

[MacLaverty]

We have an issue where a part of one of our chimney stacks just under the roof and in the loft gets wet during rainfall, it is an 121 year old house and both brick and mortar are soaking. It has been happening for a while, getting wet when raining about 4/5 bricks down, dries out when not and rinse and repeat. We have had roofers out to inspect the chimney and flashing and have said no issues that they can see. Flaunching at the top and chimney caps have only been done in the last 6 months. It is not showing through to the main attic bedroom though which means it is an isolated damp patch and luckily only in the loft. Just wondering if this is common in old chimneys where it is just brick and mortar saturation from the exposed part and damp is soaking downwards or is there a wider issue? It does not happen to the other chimney stack on the opposite side of the house.

 

[blup]

Is the flue ventilated, are there soakers under the stepped flashing?

Blup

 

[Wayners]

Seal bricks with stormdry may help

 

[aveatry]

I was experiencing the same thing although the flashing looked ok I was getting wet on the inside so I took out the mortar from the flashing and re done with lead mastic and so far its been ok. Also the same as you that the leak was only during heavy windy rain and it didn't manage to get itself all the way down the attic stack and reach the bedroom below.
My flashing looked slightly different to yours Im wondering if the wind is blowing the rain through the overlaps