Is it true that Firebricks crumble if exposed to water.

[robertsang]

I went to the mason supplier whom I trust and told him I was thinking of building a pizza oven and needed some firebricks. They have them for 1.25/ech , red (soft), yellowish & redish (harder) , not sure what the density indicates, but he said the harder are for higher temp, but then he cautioned me on getting them wet, he said if I get them wet they will crumble like a cake, he said leaving them in the rain will cause them to crumble. People who use them to build open pit fireplace have problems with them crumbling when rain gets to them so he always tell them to use a metal cover.
Now I've read the instructions and it says to soak them before cutting & before applying mortar.
Can anyone confirm that this is a true statement, or is it just if left exposed to really long periods of moisture that they fall apart. I imagine that they will never be soaked after oven is built, but I' concerned that I culd have a pllet next to the build site which could get soaked and fall apart in some heavy rain, if left uncovered. Any advice is appreciated.
-rob

[egalecki]

Re: Is it true that Firebricks crumble if exposed to water.

mine sat out all summer while I was building, they didn't crumble. They also sat in water while soaking, no crumbling. This is not something I am familiar with- my inlaws had an outdoor grill thingy made of firebricks for years, no cover, and it didn't crumble either, until someone ran into it with a car...

[dmun]

Re: Is it true that Firebricks crumble if exposed to water.

Yeah, that's not true. Brickyards store them outside, after all, and I kept mine out in the rain for the better part of a year with no difficulty. What does he think they are, adobe blocks?

Even if it were true, your oven will be enclosed and dry.

[robertsang]

Re: Is it true that Firebricks crumble if exposed to water.

Thanks for the insight, just to be sure I'm soaking a few I got as samples in a 5 gallon bucket ... I'll see how they hold up, if they fail then I find a different supplier.

[Johnny the oven man]

Re: Is it true that Firebricks crumble if exposed to water.

The only problems with leaving fire bricks out in wet weather for a long period is that they get mouldy/green.

[Frances]

Re: Is it true that Firebricks crumble if exposed to water.

Some of my left-over firebricks have started crumbling a bit after being left outside for an entire rather cold winter... so a lot of wet freeze-thaw cycles will do it.