soundproofing a very large empty room

[dta]

I'm trying to find out options for soundproofing a very large industrial garage.  The room is roughly 76000 cubic feet (45w x 38d x 20h).  There is a large wooden rollup garage door and two large windows (4 x 12 ft).  The construction of the walls is brick on two walls and masonry on two walls.  I'm looking for a fairly inexpensive way to soundproof the rool up door and the windows so we can keep sound in.  We run heavy duty machinery with sound levels that run up to, I'm guessing, 95 db.  Any ideas?

[boborther]

dta,
You could easily treat the wooden door with some SSP closed cell foam mat. The foam mat would be applied with ordinary contact cement. This would help deaden the machinery sounds escaping through this door, especially if it is a wooden door. Wood transmits sound to a very great degree. The windows could be treated with window plugs,and as in both instances, the thicker the mat the better. Go to:
http://www.soundproofing.org/infopages/windowplug.htm
and read up on the windows, and also go to:
http://www.soundproofing.org/infopages/garage.htm for the garage door.
Thanks
Bob O.