The hearth questions and progress pictures

[asudavew]

Re: The hearth questions and progress pictures

Lots of pics.

but check out my thread

I built a form and poured the perlcrete where I thought my oven would be.

[George T]

Re: The hearth questions and progress pictures

Thanks Elizabeth. I looked at your pictures the other day. Looks good. We did get our structural layer put in today....was hot and humid here today too. I plan to do my perlite and portland tomorrow I have noticed that some just pour it where the oven floor is. seems like a lot of work to build that form. But maybe it keeps it more level?

I am a little concerned with how to really get the perlcrete good and level for the oven floor......I have wondered about putting some firebrick splits in the perlcrete like the picture in the Forno plans.....but that looks complicated too....

arghhhh....

[egalecki]

Re: The hearth questions and progress pictures

Hey George. My oven is still in progress (slow at the moment, I have company and it's been insanely hot here), so I can't tell you how wonderfully it works, but I have 4 inches of vermicrete on top of my structural layer (I used cove base as the form, worked pretty well) and 2 inches of insblock19 on top of that. I have left my form in place for now, since it is crumbly stuff, but I'm going to take it off when the dome is finished and then run a coat of either refractory concrete or the mortar over the whole thing to sort of tie it all in before I do the blanket/vermicrete coating. So, I have 6 inches of insulation under the thing total. You can see my pictures either on my link in this post or at my thread on this site- Elizabeth's oven.

[Frances]

Re: The hearth questions and progress pictures

You would only make the insulating layer smaller if you want to attach your enclosure directly to the structural layer.

...which could be quite a good idea.

The vermcrete insulation layer is a bit crumbly even when its dry, specially round the edges... so if you pour it and inch or two smaller than the structural hearth and then fill the gap with concrete (making a kind of concrete frame round the insulation), the exposed edges will be stronger. Or you can leave out the concrete edge as Drake said and build your enclosure directly on the structural hearth - that will also make it all a bit stronger.

This is what I would do if I built another oven... but having said that, if it seems like too much messing about, your oven will work perfectly well if the insulation hearth and the structural hearth are the same size.

[DrakeRemoray]

Re: The hearth questions and progress pictures

Yes, you can pout both layers at the same time. You would only make the insulating layer smaller if you want to attach your enclosure directly to the structural layer.

Hope that helps,
Drake

[George T]

I bought my material for the hearth. Both the insulating hearth and the structural. Can these both be poured the same day? Do I pour both the same size? The instructions say you can pour the insulating hearth smaller....how much smaller? Sorry for all the questions..


Below I have started my pictures to show progress
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