An adjustable mounting assembly (70a/70b) for installing solar cell modules (58) on a building surface (34) is disclosed. The mounting assembly (70a/70b) includes a mounting device (74), a stud (114) that may be threaded to the mounting device (74), a clamping member (142) that may be positioned on the stud (114), and a nut (128) that may be threaded onto the stud (114) to secure the clamping member (142) to the mounting device (74). A nut (126) is fixed to the stud (114) at an intermediate location along its length. This fixed nut (126) may be used to tighten the stud (114) to a mounting device (74), and furthermore may be positioned such that the stud (114) does not extend into a slot (90) of the mounting device (74).