Floor Insulation

[tartar3]

Hi all just have a quick question, I have been searching the forum about floor insulation and can't find the answer. Can I put the soldier bricks directly on top of vermiculite concrete,I am concerned that it will not support the weight of the oven

[cobblerdave]

Re: Floor Insulation

G'day
Yes there is no problem with the insulation layer supporting the oven whether its pearlite cement or ceramic board. I know you can dint the surface of both with a fingernail but the weight is spread out so its supported. All the ovens here are built directly on the insulation
Regards dave

[Gulf]

Re: Floor Insulation

Tarter3,
Dave is right about that. I just want to elaborate on vcrete strengths. A 5 to 1 (vermiculite to portland cement) is what is recomended for the floor. Vcrete over the dome is usually about 10 to 1. You probably have picked that up already. I just wanted to be sure .

[texman]

Re: Floor Insulation

just a recommendation: use some FB Board or equivalent for the actual base under the floor bricks. I think the gain in efficiency and heat retention is easily justified.

Texman

[GianniFocaccia]

Re: Floor Insulation

I used both vermiculite (bottom 3.5") and 2" calcium silicate board on top. After a number of 800-900F pizza sessions the bottom of the support slab remains at ambient temp.

[hungng]

Re: Floor Insulation

When you look at the vermiculite slab you think there is no way that it will support the dome but it does and is surprisingly strong.

[stonecutter]

Re: Floor Insulation

I used both vermiculite (bottom 3.5") and 2" calcium silicate board on top. After a number of 800-900F pizza sessions the bottom of the support slab remains at ambient temp.

Question...are you finding the floor too hot?

[TropicalCoasting]

Re: Floor Insulation

Question...are you finding the floor too hot?

is the floor soap stone?

[GianniFocaccia]

Re: Floor Insulation

Question...are you finding the floor too hot?

Initially, when I relied on only dome-reflected flames to heat the floor I could only get 400-500F in the center of the floor, making for some pretty doughy pizzas. Now, charging the floor with coals for several minutes, I have been able to get both dome and floor 800F.

The last few sessions this has worked well for my neopolitan pies using Caputo 00 and sourdough starter.

[cobblerdave]

Re: Floor Insulation

G'day
You got to be happy with results like that... Good look' pie
Regards dave

[wotavidone]

Re: Floor Insulation

Gunna have to work on my dough. I can't get cornicione like that. I get a puffed up crust around the outside, but not that good.
I'm thinking a bit wetter (I'm at 60-62%), and a little less handling.
Also our shops finally have typo 00 at reasonable prices.

[NCMan]

Re: Floor Insulation

Since you all are on the subject of hearth insulation...If I poured a concrete slab, then set a 2" insulation board, then the hearth bricks, would that work well enough, or is a pour of vermiculite preferred under the insul board? I'm still in my planning stages and wondered about that. I know which way works best, just wondered about the effectiveness of just the insul board under the hearth bricks. Or, could I just beef up the insul board to a double layer, perhaps? Pros and cons?

[david s]

Re: Floor Insulation

The cal sil board is about twice as good an insulator as vermicrete, but costs more than double vermicrete.
50 mm of it is sufficient IMO, but if you want more it wouldn't hurt.
The cal sil is dry when you place it while vermicrete is wet and the water needs to be removed for it to work. Covering wet vermicrete with calsil will trap the water in and it will take a long time to remove it.

[NCMan]

Re: Floor Insulation

The cal sil board is about twice as good an insulator as vermicrete, but costs more than double vermicrete.
50 mm of it is sufficient IMO, but if you want more it wouldn't hurt.
The cal sil is dry when you place it while vermicrete is wet and the water needs to be removed for it to work. Covering wet vermicrete with calsil will trap the water in and it will take a long time to remove it.

Thanks. That helps. During normal conditions, how long would be best to let the vermicrete dry before covering it, if I went that route?

[david s]

Re: Floor Insulation

Thanks. That helps. During normal conditions, how long would be best to let the vermicrete dry before covering it, if I went that route?

I did some test on this and documented the results. The test was done in ideal drying conditions. Hope this helps.