Wet FB board

[Poetryart]

Even though I covered my "in progress" oven, apparently some rain weeped in under the tarp a few days ago. I have FB board under my firebrick floor and it seems really moist on a couple sides. It's even started showing some mildew on one side. Structurally it seems fine. I have only 2 rows left to finishing the dome and was hoping to add a layer of cement/vermiculite to the counter area this weekend. I have concerns about sealing in this much moisture, though. Should I worry about that? I want and/or need to raise the level of the counter, which I'm also expecting will hold the unmortared floor in place. On top of this counter I want to "tile" it with stone slabs and grout them in. What happens if I take out the first two or four fire bricks in the entry and replace them with the same stone? Is the heat an issue in the entry? I have small gaps in the floor between the oven and the entry, and now realize they maybe should have been bigger. I hope all this makes sense. Sorry if I'm rambling... I need advice...

[azatty]

1. Wet board isn't a big deal. It will dry out just fine. My board has been soaked, and as long as you don't crush it, the water doesn't hurt it. Scrape off the mildew and let the board dry before you cover it permanently.

2. Different materials have different expansion and contraction rates when exposed to heat. How hot will your landing bricks get, and how much of an expansion joint will you leave? Right at the edge on the outer arch, the bricks might be nearly ambient temperature, and you won't have much of an issue. It really depends on your entry depth and your vent transition. My oven has a more shallow entry, so I have a cosmetic outer arch that is not physically connected to the landing or vent, but looks like it is.

[brickie in oz]

Originally Posted by Poetryart

with stone slabs

What sort of stone is it?