regular red brick ok?

[Tory]

I've seen a few videos on youtube showing people making their own WFO's.

It seems like some people are using red bricks to build the dome. Is this safe to do?
I was told NOT to use red bricks because they are not tempered to handle the heat of a WFO, especially in the dome.

And if it's not ok to use these bricks, why can people make domes out of mud? I would think the bricks would be better for heat
than mud is.

Or is it just that you shouldn't use red bricks as the 'floor' of the oven?  What material is best to use for the floor of the oven?

Any advice would be appreciated. Thanks in advance.

[Tscarborough]

The color of the bricks is meaningless.  It is the type that matters.  Old common brick that are solid with no holes or frogs will generally work, although you may get some spalling over time.  Modern face brick that have holes or frogs are not suitable, but if they are solids and not wire cut they will generally work fine.

[Tory]

Well, I used the term 'red' brick simply to identify which type of brick I meant. I wasn't meaning that their color had anything to do with it.

If I had simply said "brick", then someone would have undoubtedly said "what kind of brick?"

And I don't know what you mean by 'frogs'.

[adios pantalones]

"Red" brick really doesn't tell us anything.

A red brick could be cement brick (big no no), a solid waterstruck brick (maybe OK), a modern face brick (cored or not), or a fire brick of some sort (preferable; usually not red, but some are colored).

Each of these types has a different suitability for cycled heat work, so the color may not be a good indicator. Tscarborough's answer is right.

As a side note- there are cream colored common brick in Australia that will stand incredible heat- they are effectively fire brick, and many a high temp pottery kiln has been built of them.

[TXCraig1]

And I don't know what you mean by 'frogs'.

It is an indentation in one of the large faces of the brick.