Setting floor tiles in salt?

[karl]

Hello,

I am building the Pompeii oven and following the Forno Bravo descriptions. Very nice and ellaborate descriptions. Extreemely helpful. A local craftsman told me that he would recommend to set the floor tiles in a layer of salt (NaCl). Have you heard of this way of laying the bricks before? Does the salt have an insulating effect or a heat capacity effect? Will it be transformed in any way during heating?
I was curious about his advice, but it seemed that the craftsman did not know the real reason for using salt. Just said it was common practice.

regards from karl

[mfiore]

Re: Setting floor tiles in salt?

Karl,

Older ovens used salt, and other things like broken glass as insulators. These make terrible insulators. There are much better materials for this purpose. (I'd refer to the Pompeii plans).

If the salt is used just to level the floor bricks, I also think there are better suited alternatives. Fire-clay/sand mixture is commonly used. If any moisture gets into the floor, the salt will obviously dissolve and be gone.

Good Luck

[nissanneill]

Re: Setting floor tiles in salt?

Further to 'if the salt gets wet' issue, it will have the effect of what we call 'rising salt damp' out here in Australia.
Houses built in poor soils with inferior waterproofing, the salts in the ground continue to rise up through the bricks (as they are porous) and on the outside in a white scale appearence slowly destroying the bricks. They crumble and fall apart.
I would not use salt at all for the construction at all for this very purpose.
Straight fireclay (which has a portland cement texture) would be adequate or if you didn't have that, just a fine dry sand would suffice.

Neill

[karl]

Re: Setting floor tiles in salt?

Thank you for your comments which I think sound very relevant. I will definitivly continue with the Pompeii plans!

regards from Karl