Herringbone vs. running bond (angled) floor layout Tools, Tips and Techniques Discuss Herringbone vs. running bond (angled) floor layout in the Pizza Oven Design and Installation forums; I went with 4 inches of insblock19 - was it needed, I have no clue. I did it solely to ...

[Les]

I went with 4 inches of insblock19 - was it needed, I have no clue. I did it solely to get hearth to a comfortable level vs my barbecue height. I do know it did no harm. I believe James recommends 2 inches and James knows best.

Les...

[SCChris]

I went with 2" of Calcium silicate board. The last time I measured over time at 24 hours the underside of the slab and the outside of the Calcium silicate board door were about 98F or so when the inside of the oven was 410+ degrees. At 48 hours the inside of the oven was still 230F. Since these readings I've tightened up the insulation that covers the oven and added vermiculite over everything. I'd be surprised that when I run the numbers again that I can't push this 230F point out 12 or more hours. I also feel that as I do more cooking that the underside of the slab will pass less heat as the slab dries. It would be fun to be able to cook out to 72 hours past the pizza burn, it might have me cooking more often in the WFO but I can't really say...

Chris

[Neil2]

"I'm a bit concerned about keeping it dry "

If you go with the vermiculete, you won't have to worry about water in the insulation layer.

[tfasz]

Was great to get the feedback from everyone on this, and that has helped my plans continue to evolve.

I ended up going exactly the direction Neil encourages and poured a 3 1/2" Perlite/cement base last weekend. Then I'm planning on putting 1" or 1 1/2" Insblock on top of that with some more perlite around the edges.

This should get the insulation board up off the stand were the water might get in, and also puts the oven floor at a more comfortable height as Les mentioned. Plus it sounds like nobody here has ever been sorry about using too much insulation so I figured I do a bit of both.

Thanks for the feedback all!

[timo]

If it helps, I used the same approach to insulating the hearth: 3 1/2" perlcrete with 1" SuperIso board. The board makes leveling very easy. The temps are fine on the inside wood storage; never over 100 degrees, but I would suggest maybe 1 1/2"-2" board on top of the perlcrete, if possible. I hate the idea of much of any heat leaving the hearth via the reinforced concrete.

Good luck!

[tfasz]

@timo - Thanks for the input.

If the air temp is 100 under your stand, I assume that the surface temp of the bottom of your concrete is even more. That is hotter than I would have thought.

I just picked up 5 sheets of insulation board (Insblock 19) at our local pottery supplier this weekend. Based on your feedback I might be swinging by again this coming weekend for more ...