You probably already know that you will need an engineer to review your plans and come up with the specs. But it is a good idea to know what they will likely look for so you don't have to redraw and submit it to the engineer again. That being said, post a sketch, because I don't get the picture. I am not an engineer, but...

1.) I have been told that ICF roof and floor forms, such as AmDeck, BuildDeck, Insuldeck and Lite-Deck, do not reasonable span more than 30'. I have a roof plan from a customer so only snow for a live load, spanning 32'7" and two engineers have said not good. I would like to try post tensioning, but the project is on hold and the post-tensioning institute does not respond. Maybe with post tensioning you could span 40'
for a 40' x 70' you could have one beam, down the middle the long way or two the short way for 23'4" spans. You could do a flush beam so it is no lower, or higher than the rest of the floor system. You would need columns.

2.) Do you mean maximum pitch of ICF walls on a gable end, if so there is no maximum, you could put a form on top of the ICF walls system to keep your concrete from flowing out.
If you mean maximum pitch of a concrete roof, there is no maximum, just a lot of prep work. Below 4/12 or maybe 6/12 I would use one of the aforementioned ICF roof forms and a stiff mix and anchored rebar to prevent sliding. Beyond that I would use ICF wall forms and pour in them.

This is a good roof thread

Look at Hambro, they can span the distance you require

Are you covering the entire space with the elevated slab? I assume you are interested in an ICF solution because you want an insulated slab over an unheated or partially heated garage. I think you will be happier if you do it column free.

At 40' span, regular reinforced concrete is not very efficient, although a post tensioned slab would be a good solution and provide a flat surface for easy insulating. While not rocket science, post tensioning expertise (and cost) varies greatly from region to region.

40' is no problem for bar joists and metal deck. I have no experience with Hamro, but it appears to be efficient becuase it creates a "composite" structure. Insulating will be a bit more difficult with any metal joist system.

Bruce

Bruce

Trooper4985,

Since you plan to have living space above be sure to question Hambro about excessive vibration with their system on such a long span.

If you want to clear span 40' then check out Metwood beams with camber.  Compare Metwood beams versus Gluelam and rediron beams.  Watch out for deflection in the non-cambered beams.  Although a beam with deflection may be safe, it makes the ceiling appear to be sagging.

Metwood and Hambro look good, haven't used them, but have talked to Metwood and I was impressed. the insulation and attachment of the ICFs for floors are an advantage. If you have in-floor heat insulation is needed.

I fixed the problem with the floor span... I expanded a few feet each way (72X44 to multiples of 4 for less waste) and added rooms for the utiliies, storage, brewing, hunting and pantry.  The concrete is going to be supplied by a guy I work with so I'm getting it at cost.

Thanks for the input.