Tim spent a season with Glasgow - in 2005/06 - before re-joining Irish province Ulster for a season en route to his current club, French Top 14 side Castres. On his return to Glasgow, 6ft 6in 18st Tim said: "I'm very excited to be coming back to Glasgow because I thoroughly enjoyed my previous spell with the club.
"Glasgow have been improving every year in Europe and the Magners League and I'm impressed with the ambition Sean Lineen has for the team.
"I can't wait to get back to Glasgow and play the best rugby of my career."
Warriors head coach, Sean Lineen, added: “It’s a real coup getting Tim back to Glasgow. He’ll help drive the competition we’ve got going in the second row.
“Tim will give us that hard edge we need and will increase the mobility of the pack.”
In addition to his club achievements, Tim has represented Ireland at U18, U19 and U21 levels.