2" refractory tiles or 3" fire bricks for floor

[Simonl]

Hi all,


Been on here for couple years researching pizza ovens and now it's time to build!

In Melbourne, Australia I seem to have a choice of 2" refractory tiles or use standard 9x4.5x3" fire bricks for the oven floor. I see that you guys in the US and other places use 2.5" bricks for the floor which I can't find here.

So, question for the brains trust out there is do I go 4" of vermiculite (5:1) concrete with standard medium duty fire bricks, or do i go 5" of vermiculite concrete base and use 12"x12"x2" refractory tiles for the floor?

Im already commited to the oven floor height hence the thickness combination needs to be around 7 inches.

I'm not planning on cooking on multiple days, only maybe once a week for pizza or a roast so I'm trying to find a happy medium of heat up time vs heat retention.

Thanks in advance for your help. Great forum. You guys all rock!

Simon

[david s]

The decision rests mostly on the kind of cooking you intend to do. The thicker the floor and walls are the longer they will take to heat up. This of course also increases the fuel consumption. But the more thermal mass they’ll contain which extends retained heat cooking time.
Modular cast ovens are usually thinner and also have thinner floors, having found an optimum all round performance to be 2” for both dome and floor thickness.Unfortunately, for brick builds, 2” wide brick joints are not sufficient for structural integrity, so a full brick width of 4” is required. In order to maintain good thermal balance between floor and dome, a similar thickness should be used. Thus most brick builds have a 3” floor, or if more thermal mass is required, bricks turned on their sides for a 4.5” floor thickness.

[Simonl]

Thanks David. I think you told me what I had suspected all along. So a 3" 76mm thick firebrick for the floor set on 4" of vermiculite concrete is not over the top.

These same bricks will be cut in half and used for the dome followed by 3" ceramic fibre blanket and a vermiculite render.

Cheers,

Simon

[david s]

Yes, that’s the usual floor:dome balance for brick builds.