Hello
There is a book called "The Old Toughs" which is the nick name of 2nd RDF.
The regimental depot was in Naas, Co. Kildare (where recruits were generally trained for this regiment)
This book details the arrival of 2nd RDF in Gravesend (Kent) about 1911 and then their service at the Western Front during 1914/18, ending with the disbandment of the regiment in 1921. Soldiers who died are individually detailed.
I believe the book was compiled and published on behalf of the RDF assoc., it will tell you a lot about the conditions and locations your ancestor served in.
Regards
Billy