A few questions from Austin TX

[Lagniappe]

Still figuring out how to properly post - hopefully this works.

First of all many thanks to the many contributors that have allowed me to even get to the point of asking these questions.

So I have successfully poured my foundation, built my cinderblock base and poured my 4" concrete hearth. Feels good to be this far along, but now I am hoping to get some advice.

I read in a post (cant find now) that it is a best practice to use concrete pavers below the floor insulation. It raises the floor a couple inches and allows a path for moisture. My question is - is this accurate, still recommended? Since I cant find much about it, was wondering. If yes, are these pavers mortared down or laid loose?

Second is around firebrick in Austin TX. I purchased 125 from MPI just to get myself started and then read a bunch of negative reviews about firebricks from Elgin TX. I have no idea if these came from Elgin but I did notice about 1/3 are much brighter (almost white) and the rest are a bit duller/sandy color. Should I be concerned about either?

Any advice for local suppliers of insulating fibreboard?

Hoping to make some progress on cutting the floor bricks and half bricks for first course this weekend. Attached pic is just to show the foundation. I layed the firebrick down just to give me a sense of scale. Right side will be an Argentine grill. If you see any major issues in the foundation, please let me know (please be kind as there is not a lot I can do now)

[Gulf]

Lagniappe,

Welcome to the forum. I'm linking Tscarborough in on this discussion. He is from Austin as well. He would be a great resource for information about local materials. He is also an expert in all things WFO.

In the meantime, you could check with MPI about who is the supplier for their fire brick. I'm not sure who MPI's supplier is, but Elgin Butler has gone through a lot of changes in the last few years. Maybe, someone else can share if those changes were for the good or not.

[cnegrelli]

You'll fine Tscarborough's build thread here.

[Brick Oven Nick]

Hi Lagniappe,

Congrats on kicking off the project. Looks like you are off to a great start. I like the color of your common brick you have there.

Im in Austin and am on the final stages of a 40" oven build. I just figured out the proper way to actually post things, by starting a build thread, and I'm almost done with my build, so you are already way ahead there! I think maybe I'll post my pics in a tread as I'm just finishing. Anyways, as mentioned, Tom is in Austin and was really nice and helpful to me in answering questions. I also sourced my firebrick from MPI and my order said they were Whitacre Greer Firebrick, not Elgin, but you can double check your order with MPI. I have been happy with the brick so far but I'm just now lighting my first small fires and haven't cooked anything yet. I sourced the fiberboard and blanket from Forno Bravo and perlite from MPI.

On my build, I applied a 1.5" insulated concrete layer to the hearth and then placed the fiber board on top of that. I'm not sure if that's great or not, but I wanted to raise the fiber board off of the hearth concrete to avoid moisture absorption from the hearth into the insulation, but didn't want the height of the oven floor to be much higher off the ground as if I used a thicker material there. Russell's build shows the layers he used under the cooking floor, and others here may have better advice for you, but that's what I did.

Good luck and enjoy!

[Lagniappe]

Thanks a lot everyone.

Nick congrats on getting to the fire lighting stage. Good advice to check the receipt, I found it in my truck and it says Brick, Fire Buff (Whit/Greer), so looks like they are same as yours. The two different colors still seems a little odd, but unless someone says otherwise, I am not going to worry.

Appreciate the comment on the common brick. They are a craigslist special, about 1/2 new and 1/2 salvaged from a remodel, 1500 bricks for $200, seems like a deal. Should be enough for the outside of the foundation, plus the walls for the Argentine grill and counter walls. I have no clue how to lay brick, hoping all the instruction and practice on the WFO will give me some confidence.

[UtahBeehiver]

Lagniappe, not a term I hear often in the western US but quite common in the NOLA region. You from there or have Creole heritage?

Chose the best face and square bricks for the floor. Second best for the back half of the dome and last for the front half of the dome (no one sees these bricks once the dome is done. Tscar will be a great material and advice source. He also did some great non linear brick work on his enclosure.

[Lagniappe]

Thanks a lot for the advice & for all the tips given to others that I have learned from reading this forum.

I did my undergraduate studies in New Orleans, always liked the idea of Lagniappe. A little something extra.

[UtahBeehiver]

Nothing wrong with a full soldier course but just be aware of the outward forces of the dome with this configuration. It may require some bostering around the soldier course.

[david s]

Nothing wrong with a full soldier course but just be aware of the outward forces of the dome with this configuration. It may require some bostering around the soldier course.

I agree. As the base of the dome is the structural weak point of the form (think of the vulnerability of an eggshell at that point if cut in half), then a vertical joint the height of a full brick length is going to make that point even weaker and an encouraging place to begin a crack.The big advantage of a soldier course, if your floor is inside the dome, is that you won't be scraping away at a brick joint with your metal peel. The other advantage is that it gives you slightly more height at the perimeter so you could place things like bread loaves closer to the walls.

[Lagniappe]

I made some progress. I cut the perimeter of the floor bricks and all the half bricks for my first course. Won't be doing a full soldier course like my initial post showed.

I still haven't sourced my insulating floor board yet, although I haven't looked very hard. Wanted to make some progress and test out the saw.

Anyone see any issues with my cuts before I get too far off track? Really struggled to figure out right way to frame up the opening. It is 20" and will be a 42" oven. I have seen lots of posts and advice on the arch and feel like I need to get my entry correct to get the arch right. I guess it is set up for a half brick inner arch, hope that is ok.

[agrasyuk]

I can't answer the arch question as tiny pictures make it is very hard to see details of your entry mock-up. At this point though I don't think you are off-track.

[Lagniappe]

You are right, the pictures did come through tiny.

I tried several times with multiple devices to load in jpeg format. I kept getting an error about the extension of the file did not match the content. The only thing that seemed to work was GIF format. Let me keep trying or if any advice out there, let me know. Not sure why it worked in jpeg in first post and then not in this one.

[jonv]

Just remember that if you want to tie in nicely with the dome you'll need the best part of a full brick's depth at the top of the entry arch... worth taking a measurement from the centre of the dome to the inner face of the arch to make sure you haven't got the arch too far forward, if that makes sense.

[Lagniappe]

Tried again with the picture format - hopefully this works better.

Original note:

I made some progress. I cut the perimeter of the floor bricks and all the half bricks for my first course. Won't be doing a full soldier course like my initial post showed.

I still haven't sourced my insulating floor board yet, although I haven't looked very hard. Wanted to make some progress and test out the saw.

Anyone see any issues with my cuts before I get too far off track? Really struggled to figure out right way to frame up the opening. It is 20" and will be a 42" oven. I have seen lots of posts and advice on the arch and feel like I need to get my entry correct to get the arch right. I guess it is set up for a half brick inner arch, hope that is ok.

[JRPizza]

While you are waiting for your floor board it would be a good time to make your inner arch form. This will allow you to place the form where you want your arch, then make sure that a full brick at top dead center will intersect the dome or you will have problems keeping it round if the arch is too far from the center of the oven. That's what Jonv is talking about above. Here is a sketch and picture that may help. In the sketch you can see that the brick can move a little to left or right (outside or in) and still make for a good transition and I made mine stick out a little more so I could build my vent arch over it with a heat break. Are you planning on a hemispherical arch or a flat one?