refractory concrete hearth? Newbie Forum Discuss refractory concrete hearth? in the Good Background Information forums; Hi guys, I'm part way through a build, refining the design as I go. For a bunch of reasons to ...

[David Reekie]

Hi guys,

I'm part way through a build, refining the design as I go. For a bunch of reasons to do with limited space and a liking for the small and efficient over the big and meaty, I'm going for a cast refractory concrete dome, 33"ish diameter, and 2"ish thick. I know this is a lot thinner than the standard half brick, so there will be less thermal mass - that's a good thing as far as quick heat-up goes, but I know I need to be very careful on the insulation to try to keep the heat in. I also know there has to be a much higher chance of it collapsing than a brick dome - that's a risk I'm prepared to take ;-)

Anyway, my real question is about the hearth. With a thinner than usual dome, a thinner than usual hearth seems pretty sensible. So I'm thinking 2" or a touch less. I'll have a bunch of refractory concrete available, and I'm wondering if anyone has used that for a hearth, or has any good thoughts about whether it will be a good thing or a bad thing. I've seem quite a few refractory concrete domes now, but no hearths - is there a good reason why which I'm missing?

I know you can get thinner firebricks, and I know they are well proven, so they are obviously an option. But I don't mind experimenting and being the fall-guy for something new - unless someone knows a good reason not to!


Dave.