WO Grenier joined the army in 1981 as a reservist with the 10th Engineer field squadron at Quebec City. He participated at 2 major’s exercises, FallEx in Germany and RV85 at Wainwright. He then transferred in the regular forces as a member of the heavy equipment troop with 5th RGC. In July 1994, he is posted at CFB Shilo, sent back to the regiment in 1996, and posted once again in 2002, but this time at CFSME as instructor for the heavy equipment troop, and 2 years lather as standards rep. During his stay at standards, he participated at the creation of the distance learning package for the heavy equipment course and won a gold awards from the Canadian Society of Training and Development for the creativity of the package. In 2008, he has been posted back to 5th RGC and was in charge of the Support troop until his release.

He participated at many missions with the United Nations; Cyprus during winter 1990-91, then former Yugoslavia during winter 1992-93 and summer 1993, Haiti at fall 1996 and Afghanistan during summer 2009.

WO Grenier will work at Home Depot and take care of his centenary house at St-Basile, in suburbs of Quebec City.