Dome and Floor Insulation...

[wthwaites]

Hi All!

I'm sourcing my insulation materials for my build - a 42" inch oven.

In the Forno Bravo manual it recommends 2" floor ceramic insulation board for the oven floor along with a 2" thick blanket for the dome. I'm assuming that this is the minimum standard since I've also read in a few threads that more is better? Would it be ideal for more insulation?
I believe that I am getting 2" insulation bricks for underneath the oven floor; so that thickness will not change. However I am considering an additional 2" of the blankets for the dome. Is this overkill??
What is too much and considered to be waste? Thoughts?

[RandyJ]

You can not use the insulating brick as the floor of the oven. They are very soft and not ment to cook on. As for amounts of insulation i would say 2" of calsil under the oven is a bare minimum 3 to 4" is better but you will see diminishing results as you go beyond that. Ad for the dome i would say 3" is good. If you can afford one more layer it could not hurt but I would do at least 3". I like to buy mine from Mcgills wearhouse. They have very good quality and prices.

Randy

[wthwaites]

You can not use the insulating brick as the floor of the oven. They are very soft and not ment to cook on. As for amounts of insulation i would say 2" of calsil under the oven is a bare minimum 3 to 4" is better but you will see diminishing results as you go beyond that. Ad for the dome i would say 3" is good. If you can afford one more layer it could not hurt but I would do at least 3". I like to buy mine from Mcgills wearhouse. They have very good quality and prices.

Randy

Sorry, I meant that I would be using the insulating bricks underneath my cooking floor instead of purchasing a ceramic fiber board. I may be able to get the insulating brick for free.
I will look into McGillis warehouse. Thanks for that!

[UtahBeehiver]

Free is good, IFBs is a decent option for under the floor bricks, not quite a good a K value as CaSi but worth using if free. They are typically very expensive, 4-5 bucks a piece. Depending on how many you have access to it may be worth placing on edge, IE 4" instead of 2.5" to give you more insulation thickness to offset the lower K value.

[wthwaites]

Thanks UtahBeehiver!
Once I am able to get the bricks, I will have more than enough to be able to place on edge. Thanks for this response - I always look forward to your input!

[wthwaites]

Free is good, IFBs is a decent option for under the floor bricks, not quite a good a K value as CaSi but worth using if free. They are typically very expensive, 4-5 bucks a piece. Depending on how many you have access to it may be worth placing on edge, IE 4" instead of 2.5" to give you more insulation thickness to offset the lower K value.

UtahBeehiver In addition to the IFB's, i also managed to came across what I believe to be Ceramic Fiber board lying around. I can still use the Ceramic Fiber Board despite being 2nd hand right?
Can you suggest the best combination for optimal insulation? I was brainstorming the option of a initial bottom layer for IFB's on their face or side, and then placing the ceramic fiber board on top? What do you recommend?

[wthwaites]

I also have been watching some instruction videos from Melbourne Firebrick Co. and saw that they pour a thin refractory castable layer on top of the CaSi for added thermal mass before laying the floor tiles.
Is this a good addition or is it unnecessary?

[UtahBeehiver]

Do you have any info/specs on what you suspect is CaSi? There are similar looking materials that are not necessarily CaSi board. Key info is K value and compressibility. A "close-up" picture may help, It is too difficult to see exactly what this material is. What is the thickness, what is the blue coating? How are you planning to use your oven?

[wthwaites]

Do you have any info/specs on what you suspect is CaSi? There are similar looking materials that are not necessarily CaSi board. Key info is K value and compressibility. A "close-up" picture may help, It is too difficult to see exactly what this material is. What is the thickness, what is the blue coating? How are you planning to use your oven?

No information/specs to provide. Both that and the IFB were being disposed at a cement factory as they got wet outside a warehouse so they could not installed because of moisture etc. Hopefully these pictures can help. Dimensions are 24" x 39". The thickness varies; either 1 1/2" or 2 1/2". The long strips are 3" thickness. Don't know what the blue coating is.
How I plan to use my oven? - pizzas on day 1 with the high temps, basic baking or slow roasts as the temperature lowers over time. My aim is to have the oven maintain various temps over the span of a weekend with various activities.

[Petter]

I would put the IFB under the board since they will stop rain water to be sucked from the slab and soften the board.

[UtahBeehiver]

By the pics the material looks fairly dense, so I do not think compression will be a factor other than that, don't know. You will have to make the choice. I do agree that if you use the material it should be on top of the IFBs and with the combo IFBs and ??CaSi?? of 1.5 or 2" you would be good on the type of cooking you want to do as far as floor insulation. Dome and door insulation are also key.

[wthwaites]

Awesome, I'll try this then. Should I still lay the IFB on the side for 4" like you mentioned before, or lay on face for 2"?

[wthwaites]

I also have been watching some instruction videos from Melbourne Firebrick Co. and saw that they pour a thin refractory castable layer on top of the CaSi for added thermal mass before laying the floor tiles.
Is this a good addition or is it unnecessary?

This question wasn't answered. Any thoughts - yes/no?

[fox]

I have not seen the video or know the exact products used but it sounds like a bad idea to me!
Thin layers of refractory will crack and it would hard to get a smooth perfectly flat area to lay the floor on.
If you really need to add mass then I would say ... use a thicker brick...

[wthwaites]

i posted the video i was watching to show you, but it got deleted?