Its a Building Surveyor you need (as opposed to architect, quantity surveyor or general practice surveyor) - they are qualified to diagnose damp, dry rot, wet rot, structural problems etc etc. And if it is a FULL structural survey, then he/she should absolutely crawl around the attic, pull up a floor board and do everything else that a FULL structural survey entails. As mentioned above they have insurance.
Don't know anyone in Donegal unfortunately, can recommend someone I used in Midland area some years ago now...
A