Advice please

[tenpin2]

We are planning a 32" Pompei oven. So far we have acquired some high performance white insulating bricks , 42% alumina fire bricks and 4 large square 4 inch thick 42% alumina slabs.

Our plan is to use two layers of insulating bricks for the base, followed by the slabs. Build the dome with half firebricks and then another course of insulating bricks over the entire dome.

First of all does this sound feasible?

Would we need to use vermicrete to secure the insulating brick base?

Would vermicrete be appropriate to fix the insulating bricks over the firebrick dome and also as a final application to complete the domes outer layer?

What are the ratios of cement/sand /vermiculite, and is horticultural vermiculite appropriate.

Thanks in advance
Jo

[fxpose]

As far as insulating the dome you'll need more than just a layer of insulating bricks over the firefricks.

[RTflorida]

If I remember correctly, insulating firebricks have about the same insulating value per inch as vermiculite or perlite concrete. If those insulating bricks are standard thickness (about 2 1/2"), you would need either a second layer or a layer of vermiculite concrete.
Vermicrete ratio is 5-1 (no sand) for under the hearth slab. Over the dome it can be stretched to 8-1 (again, no sand).
Horticultural grade is perfect.

RT

[RTflorida]

Wait a minute, I just reread your post.
Please clarify. Starting with your hearth firebricks, what is the order of materials working DOWN?
Should be:
Hearth firebricks
insulating layer (insulating bricks, vermicrete, ceramic fiber board)
reinforced concrete hearth slab.
Support stand

Have you downloaded the FREE pompeii oven plans in the Forno Bravo store? This should be your starting point. Read them, read them again, then one more time and keep them hand as your build progresses.

RT

[tenpin2]

Thanks for the replies and sorry for posting in different places, thought I would get a few different opinions as there seems to be many ways to do it.

Anyway, on to one of the questions.

Because we have managed to get so many high performance insulating bricks we wanted to use this in place of an insulating concrete slab for the base. So, the question is as we are using a double layer do we just dry lay these, secure them with cement/adhesive or alternatively use a band to stop them spreading?

Once the insulating base is in place do we use cement or adhesive to secure the hearth or dry lay this too.

If the answer is to use cement or adhesive what type should be used and is s the same mix used for all layers or is it necessary to use for example vermicrete for the insulating bricks and fire cement for the hearth.

Thanks everyone
Jo

[brickie in oz]

Originally Posted by tenpin2

Because we have managed to get so many high performance insulating bricks we wanted to use this in place of an insulating concrete slab for the base. So, the question is as we are using a double layer do we just dry lay these, secure them with cement/adhesive or alternatively use a band to stop them spreading?

Yes.......................

Originally Posted by tenpin2

Once the insulating base is in place do we use cement or adhesive to secure the hearth or dry lay this too.

Yes

Originally Posted by tenpin2

If the answer is to use cement or adhesive what type should be used and is s the same mix used for all layers or is it necessary to use for example vermicrete for the insulating bricks and fire cement for the hearth.

Yes

[brickie in oz]

Annoying, isnt it?

[Tman1]

So, you're told not to post the same question in multiple places and you go ahead and do it again right away? I'm in agreement with Brickie.

[tenpin2]

As I said, I posted in a few different forums to get some different opinions. It would seem opinions are like arseholes, everyone has one.

As for being an internet hardman Brickie, what's next, the cutting use of an apostrophe, some harsh spelling, an abrasive use of the quote function.

Instead of being a smartarse, why dont you offer some of your obvious antipodean wisdom and actually answer the question, or is being a the king of the brick oven more important

[Tman1]

I think you have some misunderstandings. You did not post to different forums... you posted the same question on one forum multiple times in different sections, which makes it difficult for all to know if a question has been answered. Perhaps you should go to some other forums and post similarly and see how it turns out. I've seen many questions answered here which I would put in the 'dumb' category... the people here are indeed very willing to help, and be nice about it.

Brickie (who has answered many questions and is extremely helpful overall) has indeed given you some answers to your questions. Since it would seem by your earliest statements you have chosen to not follow Forno Bravo's plans, you can't, and shouldn't really expect too much off of the little info you have supplied.