Castable Refractory Cement In a Pail

Is this Castable Refractory Cement the same as the insulating castable? I got this for Home Depot online.

Hi Avtar, and welcome to the BrickWood forum!

The castable refractory cement you purchased from Home Depot is a fine product, but it absolutely is not suitable for this project. Premixed mortar from a bucket or pail will not work with these designs. Here is BrickWood’s FAQ on the differences among these products.

You want a dry (bagged) product like HeatStop 50 for this application. There are recommended products shown in the instructions, and if you search these forums you’ll see a number of alternative products that various builders have used in their projects.

Because you got it at Home Depot, you should be able to return it to them, and possibly at a local store rather than shipping it back.

Which oven have you decided to build? We’d love to know more!

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Thanks for quick reply. I am building the standard Barile Pizza oven with an additional prep space next to it.

So for the 2” layer in the hearth slab, I will use either the heat stop 50 or the ones i can see in the forums.

For the firebrick, I bought the high heat mortar. Is this acceptable for the firebricks?

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This is the pizza oven base with the side base for prepping.

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You can use HeatStop 50 for that. I personally recommend the Perlite/Portland cement mix, as it is less than a quarter of the cost and for this purpose is just as effective. It is completely your choice.

And yes, the Sakrete high heat mortar (dry mix) is acceptable for the firebrick. Again, you cannot use a premix in a bucket for this purpose, because it is designed to stay “plastic” when cured. The dry mix hardens and strengthens the arch structure once the oven is fired.

You will love this oven when finished, and you have already built an amazing base! Keep us posted as you progress.

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I used the 50 lbs bag of Heatstop 50 but it only covered the recess to a thickness of 1 inch. Is that enough or so I need the full two inches?

Hi, Avtar,

You need the full two inches to make an effective thermal break between the hearth and the cold concrete underneath.

Again, you can use another bag of Heatstop 50, or you can finish filling this space and maintain the effective thermal break by using the mix of Perlite/Portland cement I recommended above. As before, it is entirely your choice.

Good luck, and let’s keep talking!