Help on the slab.

[joe6r]

Good morning

New to the forum, but the information on here is excellent

I have just laid the slab the dimensions are 100 x 110 cm x 4 inches deep, it is concrete with rods inserted. My question is:

Can I build the oven straight onto the concrete? And then cook of the concrete.

I have seen people use fire bricks as the base, but as it’s a budget build it was just a thought.

The guide I was following was off the instructables website.

Any help greatly appreciated.

All the best

Joe

[chas]

Hi Joe, I'm assuming by 'slab' you're referring to the 'table-top' off which most of us build ovens... not the slab in the ground off which you normally build the supporting structure?

Regardless of whether you're going to bake down on your knees or not, the answer is you really want something more stable than concrete to slide those pizzas in and out on in case you collect grit on the way. The build threads here have various answers to that: mine was old clay pamments. The extra layer will also add mass (useful for retaining heat - you need a hot oven floor) and there's the possibility of introducing an insulating layer between the chosen finish and the concrete... maybe vermicrete, but again a bit of research here will show differing approaches.

Hope that's useful, not the wrong answer!

Chas

[oblertone]

Perhaps the cheapest oven floor material are reclaimed heater blocks from night storage heaters, often free or very cheap on a variety of sites they providde good heat retention but do benefit from an insulation layer underneath; I used 25mm vermiculite board under mine. Try a search on eBay but be warned, they are very heavy so local collection is key.

[joe6r]

Hello

Yep i mean the table top not the base lol.

Ok i will look into acquiring some fire bricks lol.

Many thanks

Joe

[cobblerdave]

G'day
If it was me building a oven on a budget, I'd even use recycled soft red with the expectation of replacing one or two over time. The one thing I would not skimp on would be the insulation. Thermalite blocks are cheap and available. Even the old school ovens where insulated with clay and straw and cow poo. Recon you'd put in as much effort in making an insulation layer from these as springing for a few thermLite blocks.
Regards dave