addition of vector3

i am getting error in c# while adding two vectors,
in class i declared

public Vector3 floorPosition;

in start function i declared

void Start () { 
     floorPosition = new Vector3(0,0.5f,-8.25f);		
}

in another function i added
floorPosition = floorclone.transform.position + Vector3(0,0,2);
Please help to get out of this error.
thanks in Advance

Vector3 floorPosition = floorclone.transform.position + new Vector3(0,0,2f);