Hello from Sandpoint, Idaho

[david s]

Sorry, no I was thinking of something like 6 mm weld mesh with around 50 mm squares so it would create a 12 mm air space.

[Huckleberry Hill]

That makes sense as. Does anyone know where you can acquire foamglass in my area (Pacific Northwest USA).
with the galvanized mesh would you put only that beneath the board? You're talking about the same mesh you would use with a stucco finish?

[david s]

I’m not convinced that pavers are the ideal material for this application. Because they are quite water absorbent. You could seal them but their interior would still be water absorbent and the sealing would make any moisture that did get in that much harder to eliminate. A material that is not water absorbent but provides space between the supporting slab and the insulation would be a better solution. Foamglass with spaces between pieces of it or some galv steel mesh would achieve this.

[SableSprings]

Pavers are worth adding to raise the board off the possible dampness of the base slab. Set them with small gaps between pavers that lead to the weep holes. Looking good!

Based on the next post by David S, I'm thinking sheets of mosaic tile might be a better option than pavers. I expanded on this in post #11 below

[Huckleberry Hill]

Hi mike, thanks for the advise! I was going to do weep holes- but just drilled holes. I like your method much better! I am planning to raise the oven of the slab with cement pavers to help keep the ceramic board dry. Good idea?
cheers
michael

[SableSprings]

Looks like your slab base is plenty stout! Form for slab looks good...since it looks like your oven will be outside, now would be a good time to put in a weep hole or two. We've had lots of discussions here about keeping the ceramic board under the oven dry. If you have a little bit of leftover drip poly pipe (1/2" diameter) or pvc, you can drill a 1/2" hole (or two ) in your cement board under where the oven will be located. Push the poly pipe just through the hole and then cut it to just below the projected concrete surface of your slab. Doing this will help you avoid hitting a piece of rebar if you decide to put in weep holes after the concrete hardens (and you need to drill ). Stuff the poly with some stale bread or paper from your cement bags to keep them from being filled with concrete during the pour. After the slab starts to firm up, you can locate the top(s) and make a slight depression around them to help funnel any water out (through the weep holes).

Hope that helps...and if your insulating board ever does get wet, the weep holes will help the water "escape" as you do recovery curing fires. Since bugs may like to make a home in the weep hole (or that nice warm ceramic board), you can use a dab of silicone seal and a piece of screening over the hole from below.

Looking forward to seeing your progress.

[Huckleberry Hill]

I've been reading posts here on and off for a few years while thinking of building a WFO. There is an amazing group here.
Originally, I wanted to do my build from scratch but decided not to for various reasons and instead purchased a Casa 2G 90 kit. It arrives today and I'm getting ready to pour my concrete hearth and will soon put the kit together.
My WFO location was not conducive to a trench footing due tree roots I wanted to preserve so I did piers and posts. I know it's not recommended to use wood but I had these treated posts so built the base with them. Here's a few pics of it so far. Cement board and rock veneer will be added later.
Cheers!