Damp Patch That Moves After Chimney Work

[davo3000@gy]

After identifying water ingress from chimney pots, chimney was repointed pots capped with suitable covers allowing air flow. chimney breast re-plastered all appeared well, after a couple of days a wet looking patch appeared on chimney breast adjoining internal house wall which seems to have gone across the wall by approx. 1.25mtrs from ground level 1mtr in length 30cm wide. after a few weeks I decided to remove the damp area and re-plaster. as it dried out the patch in question moved down the wall, still 1mtr in length and 30cm wide the adjoining breast wall has remained creating a longer piece of damp. the plaster that was re placed has remained dry the patch is now 30cm lower than it began. HELP required.

[welsh brickie]

it could be moisture trapped in the wall and finding a way out, I would wait a few months, to see if it disappears