Yes, Founders Hall has a very small 5th floor. If you look up from the southeast corner of the Alum Courtyard you will see a tiny section of building above the 4th floor. Today it is full of wires and antennae and is inaccessible to the public.
But, back in the 1970's the attic housed something very special, the art studio of Sister Helena Steffens-meier when she was artist-in-residence!
Here is a photo of Founders Hall not long after it opened in 1954.
It looks a bit different today...