Corrugated Floor Decking

[Chach]

Hi I am in the middle of framing up my base structure for the hearth concrete deck. I came across some corrugated floor decking from a construction site and figured I'd use that to support my concrete pour and this way it can stay. I framed the perimeter for 4" of concrete and every other cell gets poured with rebar. this decking is very strong and is used for the construction of floors in commercial buildings and then they usually pour 6" of concrete on top. Problem is if i lay this across my structure i get 4" of concrete in the lower section of the decking and only 2" of concrete in the high section. Has anyone done this before? it is far easier than building a wood floor to support the floor and this steel can stay there forever and supports the concrete with no shoring. If I do this I'm not sure i will need rebar across the hearth but I will use wire mesh to try and stop cracking. Any thoughts on using this FREE product?

[Chach]

This is what it looks like and I can still fill every other cell but if the decking ever fails which will be years upon years after I'm gone from this earth the concrete in the high sections may not hold. I could put rebar in the low sections to give it more structure but I don't think it needs it.

[rwiegand]

2" thick concrete is prone to cracking, though with the steel deck in place I doubt you'd see a catastrophic failure. My motto is pretty much "if it's worth building it's worth overbuilding", so were it me I'd add 2" of depth. You're still under a yard of concrete with the increased depth, which is the absolute minimum you can buy around here. If that's the case where you are the added 2" would be "free". I don't think you need rebar with the steel deck.

[Chach]

Funny you wrote this as i just added angle iron 2" below the top to add the 2" of concrete ...i agree it didnt feel right not to add the the 2" to make a true 4" pad. I may just wrap the bars from the cells in the block in the deck just because i can but rebar accross the whole pan deck probably is useless since this stuff is super strong