Are you sure you are required to have a 6" slab of concrete for this building? Usually the footers are thicker but the slabs we've poured for houses (which i suspect may be heavier then the type of building you are going to construct...maybe pole barn?) won't nearly be as heavy.
You might want to incorporate a hot water heated floor using solar or one of those woodburning whole house stoves. You may even consider a hot water heated floor over top the concrete in plywood.
I know when i built my shop i opted for a wood floor because in the winter concrete is like standing on ice cubes and it is harder on your feet standing on it all day.
Also unless you insulate those pole barns in the winter they are like refrigerators. If someone is going to be coming to a class all day you will want to make them comfortable. good luck
Words of Wisdom:
“Words that sink into your ears are whispered…… not yelled”
“The biggest trouble maker you’ll probably ever have to deal with, watches you from the mirror every morn’n”
“The only difference between a rut and a grave is the depth”
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Just remember...when it's time for the hearse to pull up..there's no luggage rack on top!
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The beauty of the Second Amendment is that it will not be needed until they try to take it...Thomas Jefferson