Dome spreadsheet calculator

[MFA]

Hello all,

Has anyone attempted to build a mortarless dome with only cuts that fit in all directions?

Thank you.

[UtahBeehiver]

There have been a couple builders talk about it but I do not think they ever executed a mortarless build. It is a lot of work to bevel/taper at least 3 sides and maybe 4. Do you want to do this for a particular reason?

Update, after Gulf posted the link, the gray matter remembered the build by LES, I believe the dome was almost completely mortarless.

[Gulf]

Here is a good discussion from a few years ago. Is Mortarless Realistic? I'm not sure if the point was brought out in this particular thread. But, I and others believe that the 100% contact which mortar creates between the bricks aids in faster heat equalization through out the dome". On firing, the apex of the dome will get to carbon clearing temperatures first. The slowest to heat are the lower courses of the dome. Imo brick which are just touching will not transfer that heat down to the lower courses as efficiently as would happen with mortared courses

[MFA]

Utahbeehiver,

No particular reason except the engineering challenge. I have not taken into account Gulf’s point about sealing and heat transfer. I am a couple years away from building and just starting to build my knowledge base to make sure I construct a pizza oven that will last and functions well. The fit of tapering is just I think it looks better and I will feel better knowing that I was able to do it.

[UtahBeehiver]

That is up to you and if you have the time resource and a good wet saw, have at it. But when all done, only the inside of the dome is what we see and mortar is a friend to will fill in the backside the is eventually covered with insulation and final coating never to be seen again. I all for tight inner joints.

[oasiscdm]

Not to be a party pooper. I think it is very possible with a shit load of patience. My first oven, i used very little mortar and that was predominantly to hold bricks in place until the whole row was completed. I also used a small amount to set the first few bricks on the next course. My new build will also be similar but maintain a brick to brick fit with no V from side to side is very doable with the right saw and making a compound mitre brick tray. This one i will make templates for each row. II used only about a 2 ltr icecream container of High temperature cement in my first build.

Lets see how i go this time as i am attempting a mortarless brick to brick fit. To hold in place i will cut two corners horizontal and vertical for a little mortar to simply hold in place but am also considering an adjustable spring steel loop for each course. watch this space.

[Jubilado]

I am planning to construct a 90 cm pompeii style oven, ordering materials soon.

My objective is to have the interior mortarless with thin joints on the exterior. On paper I can accomplish this by using a combination of alternating arch and rectangular brick tiers along with a single vertical cut. This would avoid the tedious tapering. I would love another pair of eyes to look, as there could well be something I am missing (surely it wouldn't be the first time).


I have seen a few references to refractory mortar joint sizes: Code requirements of <3/8", mortar manufacturer recommendations of 1/16"-3/8", and 1/8" maximum. Industrial equipment is often mortarless and brick manufacturers offer standard layouts without mortared joints. I think that thick joints will shrink more when the water is baked out.

Anyway I hope to avoid striking mortar on the interior and also having the look of only brick. We'll see how that goes....

My initial, recent post is "Guanajuato Build." https://community.fornobravo.com/for...anajuato-build

[deejayoh]

This would avoid the tedious tapering.

I think if you don't like tapering, you're better off using mortar

[joemyself]

Hey All,

Hopefully this question is okay in this thread. It applies to the dome calculator so figured it's fine. Anyways. I just got all of my firebrick for my build. They are "full" bricks (9.5x4.5x2.5). It wasn't until after I made all of the cuts for the first course that I realized the actual height of the bricks are 2 3/8" instead of 2 1/2". Is this normal and do you all account for this when using the dome calculator or just leave the inputs at 2.5" since the difference is so minimal? Wondering if I should just leave my cuts as is and just change the inputs to 2 3/8" for the rest of the build. Might be over thinking it - but I'm in the beginning of the build and have the mentality that everything has to be "perfect" but have a feeling that is going to dissipate rather quickly as I get further into the build LOL. Thanks for any advice.

Joe

[deejayoh]

Hey All,

Hopefully this question is okay in this thread. It applies to the dome calculator so figured it's fine. Anyways. I just got all of my firebrick for my build. They are "full" bricks (9.5x4.5x2.5). It wasn't until after I made all of the cuts for the first course that I realized the actual height of the bricks are 2 3/8" instead of 2 1/2". Is this normal and do you all account for this when using the dome calculator or just leave the inputs at 2.5" since the difference is so minimal? Wondering if I should just leave my cuts as is and just change the inputs to 2 3/8" for the rest of the build. Might be over thinking it - but I'm in the beginning of the build and have the mentality that everything has to be "perfect" but have a feeling that is going to dissipate rather quickly as I get further into the build LOL. Thanks for any advice.

Joe

I'm sure it will work with just a bit more mortar. If you haven't made all your cuts yet, you can adjust the height for the rest of the courses. You will need to adjust your IT to account for the difference in height though

[Michele Enrico]

Dennis this is the single most awesome tool I have ever seen. Thank you so much for building and sharing this.
Michele

[david s]

If you want to go that route an adjustable IT will do it, by adjusting the radius for each course as you go up, or (far easier and quicker) build a cast oven.

[david s]

Yes, the angles do get tighter as the dome rises. It is better to cut the bricks as you go rather than cut them all first. But that also depends on your access to a wet saw.

[Macrinehart]

Hey builders - appologies if thus question is redundent, looked through the thread and didn't see it. I downloaded v4 of the dome calculator a while back and one think I noticed is that column S, outside bottom dimension, is changed from formula to a hardcoded value on course 4. In my case the brick_width is 4.5", in course 4 the value for colum S is hard coded to 4", which changes all side angle calculations thereafter. Is that intentional?

I saw a reference that many buders reduce from half bricks to 1/3 bricks at a certain point to ease the construction, maybe this change is related?

Thanks!

Mac