If he's on that census, then he was in the Free State Army - possibly some illness, or maybe Civil War injury.
Based on details annclare has, and also directories, the hall was only used by the Army for a very short time - a year or two at most, and it no longer exists. I suspect there are no records remaining specific to the hall. Maybe keep checking the IrishMilitaryArchives for additional record sets.
Have you applied for his record from Cathal Brugha Barracks or Renmore ?
Think you have to be able to prove you are a direct relation or next-of-kin, and it takes quite a while for the search - sometimes more than a year, but usually well worth the wait.
Shane