Presumably this is your g grandfather, from Commonwealth War Graves
Egbert Powell
Private
Service No:8940
Death:03/09/1916 aged:35
Regiment Royal Warwickshire Regiment 16th Bn.
Panel Reference: Pier and Face 9 A 9 B and 10 B. Memorial:THIEPVAL MEMORIAL
Son of the late Joseph and Elizabeth Powell; husband of Jane Elizabeth Powell, of 13, Peel St., Coventry.
If you can find his service records that may tell you his job before he enlisted.