42” Pompeii in San Felipe, MX

[UtahBeehiver]

Finally making some headway after all the repours to correct the bad concrete. Courses looking good with good staggers. Probably will start to see some inverted "V" next course unless you start to bevel the sides. Remember, you only need to bevel the front or inner dome portion of the bricks where the joint surfaces conflict then fill the back side in with mortar like you are doing now. You might want to consider starting a taper inner arch now. It is easier to tie into an arch that is in place versa tying an arch into the dome.

[modified9v]

Thank you for the comments... I’m taking a piece of everything I read/see and this is where I am... yes, been ditching dealing with the arch... tomorrow! Thinking I like this Homebrew. Man, it is sticky.

[JRPizza]

I agree with Gulf in that the more you can get in the joint initially the better. I would put a brick in my IT and place it in it's intended location, marking the location of both edges if it was a first brick in the row, or the free edge if there was a brick on one side. I'd then place a wedge of mortar under the brick foot print, thin at the inner edge and thicker at the rear. I would then "try" to pack some mortar in the angle wedges on the sides, then press the brick into place displacing as much mortar as needed. Quickly I'd try to pack in the sides to fill any voids, then after setting the next brick go back as Gulf says and scrape off the excess extruded material. I was never able to get the sides filled enough to not need to add more mortar as you have to drop the brick into place with the sides sliding relative to the adjacent brick. I never did any pointing on the interior with this method and only had to backfill the sides and some of the rear joints.
Lastly, don't have your bricks too wet. I learned on the forum (can't remember who or I'd give credit) that you need your bricks to draw the mortar into their surface. If they are saturated or the imperfections are filled with residue from cutting you won't get a good bond. I had even let bricks set after a good cleaning so that they weren't too wet.

[Gulf]

Though, I did point mine during my build, I think it is best to fill the entire head joint at once. What you may want to try on the next course is to leave the mortar mounded up over and bulging out of the joint for a few minutes (15 minutes max). Then, tool the joint. Tooling is not shaving the mortar off even with the brick with the edge of the trial. It is sort of pushing the slump into the joint and removing it at same time. Dragging the margin trowel over the joint should work ok for this. If not, find another flat metal tool tha is a little wider than the joint. The shade that you have over your build will help. But, given your dry climate, covering the dome underneath with plastic or a tarp should also help between sessions.

[modified9v]

Thanks for taking the time to respond. JR, I went back and reviewed your build where you talked about mortar. That is exactly what I have going on. These bricks are super dry. They have been sitting in the desert sun for several months now. What I did was put about 5 half bricks in a bucket of water and then scrubbed each one with brush. When they were in the water they bubbled and hissed like crazy. I then set them in the sun for a few minutes... then mortared them in place.

I did notice that some of the comments on your thread were to NOT take it apart and re-do it. I think I’m going to leave it be and let gravity do the work.

One quick question, is it better to set the bricks with just the mortar on the bottom and then come back and fill in the wedges? Or, do you do the sides and bottom at the same time? I think they call that “pointing”?

Thanks again, Mike

[JRPizza]

I found just the opposite - I had some fairly dry mortar and even though I was dampening my bricks I had trouble when I first started out (see posts below). When I switched to a more sloppy mortar and just damp wiped my bricks so that the edges changed color, they seemed to draw the liquid slurry of the mortar into the imperfections/openings in the brick surface, and when that material set up provided the holding power needed. If the mortar isn't engaging into those imperfections, it won't hold. From what I found, the mortar can't be too dry or the brick surface too wet or that wicking action won't occur. When I got to the upper portions of my dome I was able to work without having to clamp my bricks in place - I kind of found the right combination to create "grabbiness"_.

https://community.fornobravo.com/for...558#post380558

[Chach]

are you soaking your bricks so they are damp...looks like the mortar is drying out to quick or the mortar is too wet to begin with and shrinks when it drys out

[modified9v]

These cracks are popping up after two days. Using standard Homebrew with the ingredients shown in the pic... Thoughts??? Start over no big deal??? Now is the time to correct this.

Thanks, Mike

[modified9v]

Man o’ man... been a month since I’ve posted with not a whole lot to report. Basically, the reasons for the delay have been weather and remodel related. It was just way to hot to work in the sun. The weather here seems to cool almost every year with the first full moon of September... almost right on the money again this year. The humidity has dropped and it is now comfortable enough to work out in the yard... well, it was!!!

I ended up going with only 2” of FB board simply because of the budget. I can’t pull anymore cash out until January and I’m not waiting that long. Layout of the board took a bit as the slab is not square. I ended up having to get one more board (24x36) and I have plenty left over to do the door. It will be fine where it is and I will live with it. The height of the floor is pretty high, but I like it... tested with the peel and I will for sure need more length to work the back but at least I can see inside without bending over too much.

Funny, I numbered all the floor bricks and forgot to take a picture for reference before I took it apart and moved it from my work bench... oopppps!!! Took a bit to get it in place but there it is. Made up my first batch of the home brew and mortared the first ring together. I used the 3:1:1:1 recipe but really think I didn’t have it soupy enough... made a second batch and used a bit more water... that was way easier to use, but I’m seeing it pull away from the brick slightly. Not sure it’s a big deal because the next day it was as hard as a rock. For reference, I’m using a red solo cup as a measuring device... Turned out that the mortar was just getting hard as I was 3/4 of the way through... I will be cutting it back as I go up with the first course.

Anyway, it’s always windy here and my shade structure is not happy... it want’s to fly. Oh, and it never rains here unless you are trying to build a pizza oven. No sooner than I got the bottom ring done the sky has opened up. Should be a short storm and I will use this time to cut about 3 courses worth of 1/2 brick.

That’s all for now, I’ll get pics up when I take the cover down and bet back to work. Thanks for following along and to those that have offered input I’m very grateful.

[JRPizza]

Yeah I went with 5" of board as I could pick them up locally, if you call a 3 hour round trip local , and saved quite a bit on shipping. It's funny that I was tracking costs down to the gnat's eyebrow till I picked up my blanket and boards - at that point I figured I was all in and stopped keeping receipts.

[modified9v]

JR, did look into what other think about insulation. Nearly everyone says if they had it to do over again they would use more. Man, those 24x36 boards are over a $100.00 bucks a piece by the time I get them to my door. I just can’t swing another 3 of em... I like the vericrete deal but I’m coming up empty on sourcing it. I will continue to look. I still have to get my insulation blanket too.

By the way, I’m finally happy with my oven stand. The steel girders worked like a champ. We jacked up the floor and installed them. We are now level and strong... will just need a touch of fireclay and sand to take out the small undulations... or, make a vermicrete slab. The search is on.

Thank you, Mikie V.

[JRPizza]

2" of floor insulation might be a little light. You should do a forum search and see how many folks that went with 2 were happy with it - you really might want to supplement with some vermicrete. It probably matters more if you are going to do some retained heat cooking - which most of us do. I always cook at least 2 meals worth of meat the day after I do pizza. Usually some chicken or beef followed by slow cooked pork.

[modified9v]

Thanks for the reply, JR. Man, I must have read your build 5 times front to back. Really glad you decided to document your build it has been very helpful.

I screwed up when I wrote my last post on the dimensions. I over estimated a little on the 53” x 53” and it DID NOT include the flue area. I went back and remeasured this morning and it’s 49 1/4” from outer dome to the outer edge of the inner arch... then, 51 1/2” outer diameter of the dome. That is 2,536 sq in. Haha... that gives me 56 sq in to the good. No way can I make that work. Oh, by the way... these are 2” thick.

Going back to my original plan I see where I had the heat break at the inside edge of the inner arch and the math worked out... but, math is one thing and working with a circle vs a rectangle is humbling for me...

I’d really like to not have to buy another board. Them babies are spendy with duty and shipping.

Since I don’t know how to use CAD I think I will cut up some cardboard pieces and see if I can make it fit. Might even try it out on some graph paper.

Thanks, Mikie V.

[JRPizza]

I used a CAD program (Freecad) to play around with how to best fit in my boards (see attached link), but it wouldn't help you fit 2704 square inches of brick surface on top of 2592 square inches of board. I had 6 1'X3' boards - the same area as yours, and I had just enough to do my 39" oven with a little left over to use in my insulated door. If you can't get more board you need to think about not insulating under your vent (may not be as important if you use a heat break, or insulating under your landing but not under the vent arch bricks. I built my outer arch on top of insulation board and sometimes think long term stability might have been better putting those bricks directly on concrete. You could also use some vermicrete to supplement your board to provide additional area, in addition to adding some depth of insulation. How thick are your boards?

https://community.fornobravo.com/for...392#post380392

[modified9v]

While I’m waiting for the concrete oven base to cure and the contractor to put in the steel beams under the slab I thought I’d tackle cutting the FB Board. Can someone tell me if there is some sort of program I can use so I can maximize my boards? The oven floor is 43” and with the gap between the floor and the first course laid I have a diameter of about 51 1/2”. When I add in the area under the vent I’m basically looking at a 52” x 52” square area. 2,704 sq inches... I have 3 FB Boards that are 24” x 36”. 2,592 sq inches... Seems like I don’t have enough, but I know it’s possible. I’ve seen it done but my search on the forum has come up empty.

Can anyone help with this?

Thanks, Mikie V.