Nate:  OK, that's a different story, then.  Weight is only an issue if you will be setting up and tearing down fairly often.  But your first post suggested that that would be the case.  And it's also a little difficult to picture a potential performance venue that will also be your rehearsal venue, but maybe that isn't what you meant.  And any time you have large set pieces that must be moved, they must also be stored, and planning for that is just as important as planning for their use when they are set up.

 

Yes, I'm sure there are lighter-weight materials and hardware available, just as there is hardware available that is professional-grade and almost indesrtuctable, but both are likely to be on the expensive side and not as readily available as plywood from Lowes.  And designers are supposed to know about such materials and how to obtain them.

 

Just to clarify, the rehearsal room I inherited when I arrived here was set up in an interesting way, and had been designed by my predecesor specifically for a show ensemble with a cast of about 24 and a showband of about 10.  High ceiling, and a fairly large room, maybe 30' x 40' (just guessing).  An L-shaped set of riser platforms had been installed along one short side and an equal distance up the adjacent long side, giving 3 levels plus the floor.  On the opposited short wall was a fixed mockup of our traveling stage set, designed for 12 mic positions suitable for 12 couples, and providing different levels for diferent staging possibilities.  (NOT choir risers, but fulfilling much the same purposes.)  In front of the set was a suspended hardwood dance floor of the minimum dimensions we needed, and over to the side of that dance floor was a wall of dance mirrors.

 

The risers had been covered with carpeting, such that I didn't realize for several years that they were actually constructed of standard 4' x 8' stage platforms.  They were very comfortable and practical for seated rehearsals, and when we needed to move to the stage set the set was there and waiting for us.  And for combined rehearsals the showband could set up on one end of the L-platforms, while in the central floor area was a very nice Steinway concert grand.

 

Such an installation was "permantent," but when we eventually moved out of that building could be easily removed and stripped down to the bare floor and walls.  That's obviously not what you need, but the more closely you can work with the "church" part of the projected use of the room to come up with a design that would work well for both uses and still not have to be torn down every week, the happier I would predict you would be.

 

It's interesting that you would mention stoppers for the back of the platforms, and a railing for safety.  Every time we designed a new stage set (and ours were always custom-designed and custom-built by our Technical Staff and incorporated controllable lighting effects as well as providing a solid performing set) I was worried about exactly the same things, and especially so in the rehearsal room on our practice set, but what we found was that the performers were not dummies, that they developed awfully good perception of their space on the set, and that they simply didn't trip or walk off the set!  The one thing that I eventually insisted on was topping the platforms with pieces of dance flooring, like the large rolls that we used on the front of our stages to cut down on accidents and injuries, and that topping not only gave a good grip for the dance shoes but cut down on the shoe noise on the set as well.

 

Yes, there's clearly a gap in the commercial market, and certainly cost is a factor, but what you're talking about is really a leap from commercial assembly-line design to custom design, which is always more expensive because it can't be sold in quantity.  We kept our expenses down by using student labor, supervised by a Technical Director who was on staff anyway, and it gave them ownership of what they had designed and built.

 

All the best, and have fun with your designing!!!

 

John