Griffin's Family of 3 foundation partnered with Chip and Joanna Gaines to work on the home of Bill Graham and his late wife, Sherry, in in Waco, Texas. Graham served 41 years in the Army and National Guard.
"Families like the Grahams, they pay the ultimate sacrifice for this country," Griffin said. "And I feel like those are the people that we need to be helping more and more."
Graham enlisted in the Army in 1965. He now suffers from spinal stenosis and prostate cancer that he said was caused by Agent Orange. A video promoting the show can be seen on the foundation website familyof3.org.
"When I found out that RG3 and the Family of 3 foundation was going to do this, it was a total shock to me that I could be that lucky," Graham said as he fought through tears. "Things like this just don't happen to people very often."
Griffin's foundation works to discover, design and support programs that help struggling military veterans, underprivileged youth and the victims of domestic violence.
Griffin is the son of two Army sergeants, Robert Lee Griffin Jr. and Jacqueline Marie Griffin. He was born in Okinawa.
The show will re-air on HGTV on Sunday at 7 p.m. ET and Tuesday at 8.