Abstract: An adjustable roof support frame is disclosed. This support frame is adapted to support roofs with access holes. The support frame comprises two lateral supports and two cross supports. Preferably, all supports comprise a first and second member, the first member having a substantially C-shaped cross section that is adapted to slidably receive the second member. Fastening holes are provided on each member for receiving fasteners and attaching the two members together. Hook members are provided for attaching the ends of the lateral supports to trusses and L-brackets are used to attach the cross supports to the lateral supports. A truss bridge member is also provided for spanning a truss and attaching two support frames together.