Floyd G. Lobban Jr., 52, a general administrator for Joseph Smith & Sons, Inc., suppliers of building materials and manufactured goods, died of cancer Sunday at Alexandria Hospital.

Mr. Lobban was born in Alderson, W. Va. He moved to the Washington area in 1943 and began his career with the Buffalo Concrete, Sand & Gravel subsidiary of Joseph Smith & Sons 23 years ago.

Mr. Lobban also was a past deputy district governor and past zone chairman of District 22C of the Lions International. He was a past president of the Largo Lions Club and was a member of Alderson Lodge No. 70 AF&AM.

He was a member of the Olivet Episcopal Church in Franconia, Va.

Survivors include his wife, Edyth Priddy Lobban, of the home in Alexandria: five children, Floyd G. IV. of Lanham, Jessica Lackey, of Bowie, Robert S., Paula O'Quinn, and Marian Lobban, all of Hyattsville, a step-daughter, Sara Barnett, of Alexandria; a brother, Charles M. Lobban, of Alderson, W. Va.; his step-mother, Christine Lobban, also of Alderson, and five grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Lions of 22C Eye Bank and Research Foundation, 91918th St., NW, Washington, D.C., or to Olivet Episcopal Church Building Fund, Franconia, Va., 22310.