The fire started on a small patch of roof at about 9 a.m., according to officials from the Greenlawn Fire Department.
The fire damaged at 10-foot-by-10-foot area and was under control before 10 a.m.
No injuries were reported, and officials did not immediately have a cause for the fire.
A spokeswoman for Suffolk County police said a call reporting a fire at the site, 544 Elwood Rd., came in at 9:13 a.m.
With Gary Dymski