Possible rising damn in living room and kitchen

Hi, our living room bay window may have rising damn. The bay is ventilated but has displayed signs of ‘bubbling’ under the paint within a year but hasn’t gotten any worse over the last ten or so. We obviously need a plasterer but Rated People doesn’t have a damn specialist in the drop down menu. Also, our kitchen has an interior wall that has the same ‘bubbling’ but also damaged sections of plaster. This wall is sandwiched between two ‘white-good’ utilities that se water… Who do I ask to review and quote? Thanks