Dome archway brick cutting?

[PeteH]

Well underway in my build now (quite a project I’m discovering!) and thoroughly enjoying reading, absorbing and admiring the builds on the forum

I’m currently attempting building my archway for my 36” Pompeii oven and please excuse my newbieness!


After spending some time dry stacking my 9 x4.5” ready tapered (3”/2”) arch bricks over a shallow form (4” deep) using shims and wedges I’ve started to mark and cut them

Starting at the top dead central brick as Utahbeehiver had shown in his diagram and going down each side in sequence
I have been using the steel edges of the brick bracket as a guide for marking the cut lines for the lower side of the brick (using a half brick below to keep arch structure from collapsing!) and the using this cut edge as template for the upper side of the next (lower) brick

My question is should I be using a string line instead as a diagonal line guide from the pivot point? If so wouldn’t that give a slightly different angle of intercept to the dome and might affect the brick placements at the transition?

thanks

Pete

[PeteH]

(Brick bracket on IT)

[UtahBeehiver]

It depends on how far off the floor your pivot is. A pic of you IT would be helpful to answer your question.

[PeteH]

HI Russell

My IT pivot point approx 4mm above the hearth floor

What I mean to say is should I be using the angles of edges of the brick bracket (ie the actual brick angles) on the IT rather than a straight line from the pivot point which goes through "centre" of brick
If both these lines intercept the inner dome face at the same point they leave the outer face at different points? About 1/8th of an inch - I'll try and do a scale drawing to explain later
I was wondering if this might contribute to the droop which I've been reading about
please excuse my not to scale drawing of my IT placement

[PeteH]

as you can see not got the hang of posting yet

[PeteH]

Should also mention IT tilts sideways as on a ball joint

[UtahBeehiver]

You do not need to be nuts on on the slope angle of the tapered inner arch and a 1/8" difference between the two methods will not be an issue. The IT is pivot point is fine. The slope angle just makes the arch/dome interface much easier and transitional since you do not need to make complex cuts.

[JRPizza]

I could not make out what you were thinking was potentially causing the droop, but I discuss my thoughts in the post below - sort of a post-mortem after I developed the droop in my build.
PS, I am not sure why you built your IT with a swivel but having the top surface of my brick holding angle parallel to the horizontal helped me keep my bricks in proper orientation. Having the end of your IT rotate/swivel means you need to be conscious of keeping the tops of your bricks angled properly.


https://community.fornobravo.com/for...405#post381405

[PeteH]

Thanks Russell

I think I’ve been looking at too many threads like yours with near perfect builds, and am overthinking it all!
Decided after posting last night to put down paper pencil and trigonometry set and get outside mix up some mortarand crack on with the build!
I will post on my thread regularly and hopefully someone will chip in if I start going to far off course!

Regards Pete

[PeteH]

Hi JR

I’m definitely making this build harder than need be!

I see your point with my ITdesign re swivelling brick out of horizontal and having checked some are slightly off level but the whole course ok as a whole
I’ll keep a check on each individual brick from now on and will attach a small brick level if I can to the top edge of the brick bracket

Thought a ball end was a good idea when moving round the circle and also can be removed quickly when need be ie cleaning up

I think I understand your reasoning behind the cause of droop and will make adjustments when meeting the arch using back bricks of the dome as guide to each course level
I'm laying bricks from the back of the dome towards the front alternating laying left and right so should meet both sides of the arch at similar time

Thanks for pointing out the flaw in the swivel!

Pete

[JRPizza]

I was checking my courses by placing a 3' level side to side, and with my droop each side was at the same height, but if I would have checked from front to back I might have caught it. If you firm up your IT you can get to where you just hold a brick in your angle and mark the outline of where it is going to sit on the brick below (I used a pencil), butter up the "landing area", and smoosh the brick into place. The inner edge will make contact and if you applied a liberal enough dollop of mortar it will squeeze out filling most of the gap in the rear. I got pretty good at packing mortar into the remaining gaps with my trowels.
PS, I understand looking at immaculate builds. If you want to see the lower end of the spectrum have a look at mine

[PeteH]

JR

You are very modest I’m

My build is a 36” corner oven (plan to roof it in a similar fashion) so I chose yours to give me much of the info I needed, your thread being quite thorough in detail only half way through the thread (although have skimmed the rest) though as quite a read!
Plan to add on bbq area & food prep area later coming off at right angles
I know you’ve drawn help from former builders and I guess each build has something thing to offer even if they’re pitfalls to watch out for!
So far realised not to change your mind on pizza oven size after constructing the base and stand! Originally planned for 32” and changed mind to 36” giving me a limited amount of space for the landing - although reading ways around this (ie wider flue and supporting outer arch over inner arch)
and obviously keep IT to a well tried & tested design
Will take my time over the next few days and get my arch in place

Thanks Pete

[DavidApp]

I overcame the droop over the entry arch by adding a support leg to my IT as I crossed the entry way. That insured that I maintained the levell all the way round. It was just a simple prop that I clamped on as needed.

David

[PeteH]

Hi David

Sorry for the slow reply think I came across something similar reading the forums with a level clamped on
Think I’ve avoided the droop by constantly checking levels and working so slowly
will update my own post soon coming close to closing my dome, but rain has stopped play, destroying my cheap gazebo after wettest May on record - it did well to last this long!
Thinking on outer arch and flue designs now whilst waiting for some half decent weather

Regards
Pete