MY 40inch CORNER BUILD

[Mr.Pizza3]

So I’m now in the planning phase of my chimney

I’ve had a few options I’ve been mulling through

And am stuck on a masonry chimney or a metal one

I’m confused by DavidS design for his metal to masonry connection for his pipe I’ve seen some drawings but I also am not sure if I want a metal chimney finish would probably go that route for weight issues only

which brings me to a few questions on masonry chimneys

1. What is the formula for casting home brew vs the regular ratio
is it just the same with a structural component added in such as fibers or metal?
Where do you find the fibers for adding in or other materials and are there multiple options?

2. I know I at least want to cast the first part of the chimney but has anyone ever tried to cast a one piece chimney? Let’s say the lower flue portion off the arch to a 2-3 foot chimney ? I have enough materials lying around to make a form big enough so cost wise it’s not a big deal


3, if going with a masonry chimney obviously there’s much more weight involved versus a metal chimney would it be recommended to have double brick walls on either side of my outer arch? To helps with strength?
I figured I was already going to do this anyway with a decorative brick

4 . can anyone provide pictures of their thermal break?
what did you do the floor? I figure I could cut it with a grinder before building the outer arch

do you just leave the floor with a gap ?



That’s it for now

currently in planning phase for the final finishing stages of the oven a lot of cool things coming

[Giovanni Rossi]

In your opinion is it necessary to perform this for oven performance or more or less an aesthetic thing?

My experience is limited but in all my reading of the Forum, the consensus is that it is for aesthetics. Some believe there's a chance those plugs will work loose with expansion/contraction of the dome. You have a complete refractory shell so you don't have any direct path for steam to your insulation layers or for insulation to fall, so all is well.

My OCD would make me fill those gaps. When I look at the inside of my dome it drives me crazy that I have a few bricks out of alignment (novice mason) and some mortar joints aligned. I am thankful that I used a kit bc I had a limited supply of bricks and refractory mortar. Had I built from scratch I'd probably still be building the dome and looking at a mountain of cut bricks that weren't cut just right. You're nearly caught up to me and I started digging for my foundation April 2022!

It has to be your call bc you're the only one who will know. No one will stick their head in to see, especially when you're cooking! Heck, how many people are going to understand what they're looking at anyway?

Keep the pics coming!

[Mr.Pizza3]

Well it’s been a month since posting here and well……


things have been going pretty well

i spent some time prepping for my new fire pit area I’m doing a whole flagstone design with a paver surround should come out well also finishing off the lawn renovation and other small projects throughout

but I was able to distract myself long enough for my dome to have a solid curing time as it’s officially been over 28 days of curing and then drying !

now unfortunately I cannot come here and say today is the day I start curing fires because I took more time then expected to finalize and finally go out and build my outer arch and chimney design

though I will say the good news is

THE HARDEST PARTS OVER !

Thats right I’m happy to say I’ve officially finished all my fire brick work and the dome officially in its final curing and drying for the outer arch so I can finally start the curing fires and get on to making pizza

[Mr.Pizza3]

Last Tuesday at 11:45 pm I put in the final key stone of my outer arch so today marks 7 days of curing and now I will let it dry for a few days and begin my curing fires this weekend!

(still have some work to do before Sunday but we will get to that farther down this )

here are some photos of my outer arch going up I did some “choice” acts and put my 10 “ blade on my hand held grinder so I could cut an expansion gap into the floor and separate my outer arch and floor entirely from the dome

i then continued with a minimum of a 1/4 air gap up the side walls of the arch

my first two initial pieces of the arch were full bricks followed by a triangular shaped brick the next brick (3rd on either side) were probably the trickiest cuts for the arch, as you can seet form the pictures the first three inches were left while the back side was cut to be vertical walls and match the width of the chimney going upward

from there the final three bricks were my only “completely cut” bricks

this left me with a clue opening 8x12 inches (which is the width of my chimney)

[Mr.Pizza3]

And yes I did decide to go with a masonry chimney in my opinion it seemed much easer and surprisingly a cheaper option

i kick my self for not seeing a text from my brick supplier telling me he has my size as i spent weeks looking for a clay flue in my area or online to purchase

but none the less I got my chimney and it is 8.5x13.5 outer dimensions with a 3/4 inch side wall

so I’m left with a 7x12 opening

which gives me 84 sq inches of area compared to a 64” which is the recommended size piping to use

they also has a 8.5 x8.5 option I also bought to bring home and decide which to run

aesthetically the smaller square may have looked slightly better and been easier to wrap with brick and also less weight but I decided for performance and I’m actually quite happy with how the bigger chimney looks on the oven

[Mr.Pizza3]

So Wednesday I began building a base for my chimney to sit on and be attached to and I also knew I wanted to build it up some to add more overall height to my chimney to get it closer to that more desired 36 inch mark (clay flues usually are only 24” )

I figured with anything I could always by another glue and cut it in half and attach it to my existing one but I don’t believe it’ll be necessary

anyway this went pretty easy I deciding to make the side bricks lay on their wider side for more stability and strength on my dome of course this tool longer to cut out the shape but the end result was worth it

I will tell you my patience was tested as I Broke the inner pieces three times while trying to cut out their shapes

luckily on my last scrap piece that was big enough to cut from I cut my final piece for the base

[Mr.Pizza3]

To help build my chimney opening I took cardboard and traced my chimney then I cut it out twisted up wire and taped the wire to all for side to make it sturdy it worked out great

here you can see it sitting to make sure my opening was sized correctly

also attached you can see what the inside of the flue looked like and where my air gap is

as you can see my final key stone isn’t cut at a slant on the bottom and that’s because I was rushing to get my last cut done at 11:45pm whilst not trying to have my neighbors kill me lol

I figured for it’s not going to affect anything and I can always go back and cut it in future so for now it’ll stay

[Mr.Pizza3]

The next day I completed my final set of fire bricks and built the base up a another two courses
while also building a back wall off the dome to carry up my air gap to the back half of the chimney

as you can see my chimney will sit on a 3 sided base and will span the gap of the 4th side had I build my base slightly larger I would have made my outer arch a half brick length more and allowed for an inner arch base on my outer arch to build up from but knowing the chimney would be self supporting with only a cap being added tto it structurally it would be alright

I could have built and attached to my inner arch and dome and I was originally planning on doing that but it worked out where I knew I could be the air gap instact all the way around and decided to go the route I did

this will all be buried under a nice brick chimney in the future so I’m also not worried about the look of the back of it

Anyway as you can see the original base being wider allowed for a cool design for the raised base for the chimney and the rear wall sits slightly higher to allows for a thicker seal to be made with a flameproof caulk

as you can also see I used the remaining mortar from each bath behind the dome wall to add some strength to its base

[Mr.Pizza3]

And today after letting it moist cure for a week I mocked up the clay chimney to it to see how it would look

funny enough I rendomlg had a 8x12 chimney cap sitting in my shed so that worked out great

overall the base of the chimney is 1 foot up from the bottom of the opening of the arch and my chimney is 24” so I have a total vertical rise of 36”

I also think it looks pretty sweet even without the decorative arch and chimney built yet


I plan to attach the chimney using a fire stop caulk and sealant and we’ll as seal the air gap with a high temp fire sealant

[Mr.Pizza3]

Some more shots of the air gap

im also happy I went this route because once I insulate and encapsulate the dome and go to build my decorative arch and chimney i won’t have to worry about having another large airgap between my outer arch and decorate arch I know some people add another thermal break but for my situation with the weight of my brick chimney that will follow I will most likely do without a second break

[Mr.Pizza3]

So now my attention is turned back to my fire pit area as I will move onto excavation and sub base prep tomorrow and this week and get on to prepping the pizza oven for the curing fires this weekend !

Still gotta crawl back in there and wire brush some of the mortar stains and residue left from the dome construction


updates coming this weekend !

[Giovanni Rossi]

Enjoying reading though your last posts, but I've already scrolled back three times to post #49 and the angle grinder pic

If you haven't already planned for it, you'll want to insulate the dome before doing your drying fires.

[UtahBeehiver]

I don't recall if you are bricking around the clay liner or not. There have been some cracking of "uninsulated clay liners, there a video poking around the blog somewhere of showing how uninsulated liners crack. IMHO, the clay liner needs some they of insulation to temper the temp differential. Gulf brick around his chimney and filled the gap between the brick and clay with vcrete.

[Mr.Pizza3]

I don't recall if you are bricking around the clay liner or not. There have been some cracking of "uninsulated clay liners, there a video poking around the blog somewhere of showing how uninsulated liners crack. IMHO, the clay liner needs some they of insulation to temper the temp differential. Gulf brick around his chimney and filled the gap between the brick and clay with vcrete.

I planned on building a decorative arch and chimney as part of the finish product once i have the dome rendered in a stucco or mortar shell

i was going to just dry fill in the chimney with the left over vermiculite I had didn’t plan on adding any Portland to it

also my plan for sealing the air gap on the sides and top was to use a fire stop caulk which basically hardens to cement

is this the common practice people use ?
or is the outer arch not reaching 600+ degrees and running lower rated silicone seal the ideal way?

any specific types or brands people are using for their sealant ?
I plan on using fire rope for the areas where the gap is larger to act as backer rod for the sealant as well

[Mr.Pizza3]

Enjoying reading though your last posts, but I've already scrolled back three times to post #49 and the angle grinder pic

If you haven't already planned for it, you'll want to insulate the dome before doing your drying fires.

I plan to follow this build three with a whole video series of the pizza build and the grinder is a whole video in itself lol

you cannot believe the force of that blade when spinning and how hard it was to rotate the grinder and move it through the air

but I kicked it on and off a couple times to get it spinning and once it got it up to speed it surprisingly worked very well!

almost too well where’d I’d do it again which writing this now I also realize how bad it could have been

but I was confident in my abilities and here we are all 10 digits !


as far as insulating the dome yep it’s a rainy couple days coming up so I currently have it covered I plan a couple days before the first fire to start getting it covered in my insulation layers

quick question ,

is it necessary to do all the layers for the fires or just need to lay down one or two ? Not sure if I need to go all out like I was planning on and have all three layers down and wired in and ready for it’s render once the last curing fire occcurs