Problem with insulating Vermiculite layer

[Nick in Laval]

Re: Problem with insulating Vermiculite layer

OK thx

Upsetting set back

Nick

[Tscarborough]

Re: Problem with insulating Vermiculite layer

With 2 layers you do not need the vermiculite.

[Nick in Laval]

Re: Problem with insulating Vermiculite layer

Each board is 2 inches thick

[Tscarborough]

Re: Problem with insulating Vermiculite layer

How thick is the board?

[Nick in Laval]

Re: Problem with insulating Vermiculite layer

Thanks for the reply scarborough. Are both nsulating layer and FB board required or can I simply remove the bad layer of insulating layer and apply the FB board on the concrete slab?

[Tscarborough]

Re: Problem with insulating Vermiculite layer

You would probably be fine from an insulation standpoint with the board over it, but structurally, 5 to 1 is going crack and shrink badly. I would break it out and redo.

[Nick in Laval]

Hi Everyone

I'm building my own 42" pompeii oven and yesterday I hit a snag. I poured the insulating layer ontop of the concrete supporting slab (see pic) and this morning I realized that I screwed up the ratio. Instead of doing 5 parts vermicultie to 1 part portland, I did 5 parts portland to 1 part vermiculite. I realilze it's a totally amateur mistake, but it's done now so I'm stuck with the problem.

Question: Is this somehow salvagable or do I need to break it and rebuild it the insulating layer?

The reason I ask is because in the FB Pompeii Oven Instruction manual, page 30 (fig 4.2), it appears as though the FB board can be applied directly on the wet concrete slab. I thought the FB had to go on the insulating slab that contains the vermiculite (5:1). I've purchased the FB Board and was planning to put it on top of the vermiculite insulating layer, so that my firebricks rest directly on the FB board.. Do I need both FB board and vermiculite insulating layer or can I do either or, inwhich case putting my FB board on top of this incorrect insulating layer would be ok?

What about the concern of the heat ultimatley transfering down to this incorrect insulating slab? Should I be concerned about it crumbling from underheath and ruining my oven? Keep in mind this layer has only portland and vermiculite.

If anyone can help me out it would be greatly appreciated.

Thx

Nick