Low Density Board

[athens]

Has anyone used low density board insted of Iso Board? The supplier told me it is rated to 2300 and should be more than enough as a base layer.
Also, if using 2" board intead os vermiculite, can I use 2 x 6 lumber for a form instead of 2 x 8?

Thanks

[gdest]

I don't know what the compressive strength or properities of the LDB but since most of the load would be spread out I would think that it would be ok.
As for the form lumber I don't understand your question, are you asking if a 6" slab verses an 8" slab is acceptable? If that is your question, there are no problems from what I can see.

[GianniFocaccia]

If you're asking if it is acceptable to pour 4" of reinforced slab concrete and then 2" of vermicrete, topped with 2" of board - yes, that will work, but 4" of vermicrete would be better. 2" of vermicrete is not that much, and it wouldn't cost that much more to go 4".

[That's Amore]

I used the 2" fb board that I puchased at a local refractory store and I would not use the low dencity board. Remember that if you place your first coarse of brick on the board in which case I would and did, keep in mind the weight of the oven and what that will do is compress the insulating board rendering it useless.

Cheers!!

[aliza]

Yeah enjoy here

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[azpizzanut]

Hello,

I think I understand your question about the form. I used 2"x10" lumber since it was low cost and available. I will pour a 3.5" top slab in the morning. The lumber in excess of the 3.5" is held securely with screws into the cinder block base and to the ends of the opposing lumber of the form. Thankfully, I have a masonry drill bit and an impact driver. I could have used 2"x8" lumber as well but it wasn't on special price from the supplier. I opted for the wider lumber since it would allow me more attach points to assure it would stay firm against the block base. Also on special price is high strength concrete in bags. I am confident a 3-3.5" slab will support my oven if it is made of high strength concrete. The next step will be to pour an insulating base for the hearth on top of this slab. I realize this sequence is different than what some others do but it is what the oven manufacturer specifies.

Best of luck to you and please keep us posted on your success.

Cheers,