On Tue, 28 Jun 2005 10:21:13 -0500, Hax Planx
wrote:

My ancient detached shop/garage has an uninsulated roof and now that
temps are parked in the 90's with full sunshine most days, the heat
radiating from the roof turns it into an oven. Things inside (like
projects) get warm to the touch and the ambient temperature soars to
about 105°(40.6°C).

I think more attic ventilation would probably help.
Use roof vents or a powered fan in the gable end. If you have soffits
add soffit vents and if not put a passive vent in the opposite gable
end. Since it sounds like the building does not have a ceiling you
could get your lower ventilation from leaving windows open.

Mike O.