Beautiful looking roof, did you use Lite-Deck? But what are the walls CMUs!!!!

ICF is no used to much here at South florida area. There's two projects going on right now in Port Saint Lucie with this kind of roof system and ICF walls (aprox. 3500 sq. ft residences), I will upload pics later. No, is not Insuldeck or LiteDeck, is WRCS concrete roof system. Go to the project album to see more pictures.

Regards,

Nice! 

If I understand correctly, you are doing a conventionally reinforced concrete sloped slab with styrofoam insulation on the casting bed of the forms, correct?

If there are no intermediate beams and/or columns, then the exterior bearing walls support 100% of the roof load, correct?

Is the forming system self supporting or does it need props/shoring?

Since you are using fiber reinforcing to minimize shrinkage cracking, are you also using a hydrophobic admix? 

What will the finish roof surface be?

Bruce

In this example the exterior walls are totally supporting the roof .  The maximum interior span is about 30'-0".

The roof concrete slab is designed and engineered to be self-supported based in the folded plate theory, and to form all this with this panels system (already precut for the shape) is needed temporary shoring support. Fortunately, the structural and shoring design for the roof is included with this panels.

There are several type of roof finish available. In this particularly case will be "Bermuda" roof, a secondary mortar finish in 16" width steps  x 1" simulating flat tiles (stamping), that personally i think is the strongest way for a roof finish. This is later painted with an approved elastomeric waterproofing. I would prefer white because the reflection.

This slabs do not require hydrophobic admixtures, because when is casted the slab is subjected to very wet condition for curing (typically here with sprinkles), and those type of admixtures do not behave well or have little effect in very wet concrete conditions.

Instead, when close to the water, beach etc, here at Miami area the city require 4,000 to 5,000 psi and a certain water to cement ratio to prevent corrosion, etc.

Anyways, several tests in recent projects down here have shown that the very stiff mix with the fiber and a good curing process can increase up to 40% the final capacity of the concrete, for example from 3000 psi to 4200 psi.

Also, some of this roofs are using integral capillary concrete waterproofing system like Penetron, Rheo mix, Darapel etc, to make the slab impervious, but personally I think this is having belts and suspenders, since they are going to put and approved waterproofing method anyways on top.

The pictures below is another example with the shoring, after the shoring removal and exterior ready for the final tile finish. Here the final span was 45' x 55'.

Regards,

Thanks. I understand now. The styrofoam panels, strengthened by the steel channels along the edges, create the casting bed. How thick is the insulation in this case? Are different thicknesses available?

Is it correct to assume that contribution of the steel channels is not considered in the permanent condition? Or do you use shear connectors (I don't see any in the pix) to enlist some composite action?

Very nice for for those of us in warm hurricane country! Any thoughts about the thermal bridging effect of the steel channels for those in tornado alley or the frigid north?

Bruce

Are the steel channnels visible underneath embedded in the Styrofoam panel? If they are there will be no thermal bridging. What makes this system different from let's say LiteDeck? I like the clean look inside. Easyly workable by other subs, like electricians and drywallers. Cost would be interesting.

The insulation is typically 4 1/2" thick, but can be varied up to 6" and the foam from 1 to 3 lb/cu ft. The channel get embedded 1 1/2" inch in to the concrete to lock the panel.

Yes, the galvanized "C"can be used as a contribution having connectors to transfer the shear and create a composite action that can increase the moment capacity up to 30% more, but on roofs generally is not considered in the structural finite element analysis and typically is not needed.

The channel on the interior are covered with a ceramic based elastomeric to prevent thermal bridging (Supertherm is one of them). I will upload later some very interesting infrared thermal photos with the system.

It is very nice to talk to experienced people like you guys here.

Best Regards,

There's a big difference structurally talking about this system and Litedeck or Insuldeck. In this system there's no need of intermediate beams and/or columns. Also there's no need of beam in the ridges and valleys. Basically this system behave in every direction self-supporting each section of the roof to another trough internal top and bottom reinforcing within the slab thickness.

The typical ICF floor and roof system as Insuldeck or Lite deck acts in one direction because of the concrete ribs and therefore is in need of interior beams or beams on the ridges and valleys to carry the system, creating some limitation on shape, pitch and clean interior spaces.

Raul,