apartment complex balcony and stairs

Question:

I've got ten balconys and stairs to build for a low Income apartment complex. there are no plans for this project.what I have come up with is to build a metal frame of 10" Jr.channel and using floor panels for concrete support.the problem I'm having is figuring out which panels to use, how thick to make the concrete, Will wire work for concrete reinforcement, how far can I span supports under pans and what to make supports out of.the balcony measurements are 8'x12' supports 8'wide. please help me figure this out so I can get a material list together and be prompt and accurate with my bid and proposal.
thank you.
Eddie

Answer:
Hi Eddie,
Sorry for the slow response...

I'm not sure what you mean by floor panels. Are you planning to use the 10" channels at the perimeter of the 8'x12' dimension? If you do, the concrete must be at least 6 inches thick reinforced with #4 rebars spaced at 12 inches on center both ways. The intend with this design is for the concrete to carry the load and transfer them to the channels at the side.

On the side of the 10" steel channels you weld L3x3x1/4 angle that will support the metal deck for the concrete. One side of this frame will be supported by the building wall and the opposite side two steel posts are required, one at each of the corners at the intersections of the 8ft and 12ft sides.

This will require two spot footings, a 2ft x 2ft spot or circular piers with sonotubes will do. This is one way of doing it.

You can run metal stud channels at 2ft centers with 8 or 10" channels at the ends with post and footings as described above that will work too.

Given the weight of the concrete I would look into the option of using wood with exterior application - it is easier to deal with much lighter material, unless the plans require concrete.