Hebel arch?

[pizzahead]

Hi. I have been reading about Hebel (Autoclaved Aerated Concrete) on this formum. Has anyone used it as a lintel into the oven? Cutting an arch out of this product seems easier than laying a brick arch or forming a concrete lintel.

Will the product withstand the heat?

Thanks
Jase

[asudavew]

I don't think anyone has tried it.

And I'm not sure about the heat because I'm not familiar with the product.


Dave

[dmun]

One memeber has used AAC as an under-oven insulation layer, with success. It's a good insulator, but I don't think it will stand up to direct contact with smoke or flame.

[Wood fired oven workshops]

I've used Hebel block for years as an under floor insulation, during my wood fired oven workshops, with great success.
Although I've not used it internally I have tested it in a kiln to 1000 degrees C with little shrinkage or deteriation. At 1200 degrees C it certainly spalls and shrinks.
If it was used as an arch I would make it thick as it certainly doesn't have great strength and be aware that being soft it you might find it wears from contact with the peel and door.

[Balthazar]

Originally Posted by pizzahead

Hi. I have been reading about Hebel (Autoclaved Aerated Concrete) on this formum. Has anyone used it as a lintel into the oven? Cutting an arch out of this product seems easier than laying a brick arch or forming a concrete lintel.

Will the product withstand the heat?

Thanks
Jase

I'm using it as my "under floor" insulation layer. It's quite brittle, but for your purposes, perhaps coating/rendering it with refractory cement would give it a tough outer layer?

[weaponx]

I used HEBEL to sit my oven on, its extremely brittle and cracked alot where we screwed it together. its been rendered and had no probs so far. Heat doesn't seem to bother it.
Its very soft, you can dig away with it with your fingernail.
Depending on the profile it has virtually no span strength and its expensive, the reinforcing material in it is no thicker than coat hanger wire, but it is very easy to work with.

[Balthazar]

I used the Hebel blocks which had no reinforcing (600mm x 200mm x 100mm), and just glued them to 6mm compressed cement sheet with Hebel adhesive. No screws or nails required.
I didn't think they were that expensive at $4 each from Bunnings.

[Wood fired oven workshops]

My experience is the less bonding of components in an oven the better.
You have to work with the knowledge that the oven is constantly expanding on heating and contracting on cooling so better to allow gravity and sound architectural structures to determine how much needs to be 'stuck' together.
The dome structure is an ideal form to allow these movements to take place and requires less bonding and bracing to hold the oven form together.