structural slab question

[rbigante]

I'm getting ready to pur my structural concrete slab on top of my block wall. Instead of framing the opening with plywood as shown in the instructions, is it possible to just span the opening with plywood resting on top of the block? Then I would add a bunch of removable legs to support during pouring of the structural slab. After curing, all I would have to do is remove the supporting legs and the plywood would stay stay. Any forsee any problems or have any comments/suggestions? Thanks. Rino

[james]

Hello Rino,

You can do that with hardibacker, and just leave it under the slab. I wouldn't do that with plywood. It would eventually rot and fall apart from winter rain, plus it is conceivable that it would get hot.

Hardibacker isn't very expensive. That is what I did on my latest oven.
James

[rbigante]

James,

that's a great idea with hardi. much appreciated.

also was thinking of possibly using a corrugated sheet metal or something along those lines.

[Dutchoven]

I concur 100% as that is what we did on our restaurant oven build...actually it was 1/2 concrete board but 1/2 in hardie is fine...held up extremely well to the wet concrete...haven't been able to look at the bottom as it is fully enclosed but the slab is A-OK and it was 6 inches thick
Best
Dutch

[christo]

Me too! it works well!

Christo

[egalecki]

I used corrugated sheet metal (decking) under mine- it worked great, but hardibacker is much easier for most people to come by.