Entry Arch OK?

[Gulf]

Yes, there can be issues tying in to the dome. Ther "dreaded droop" is one. The other is called "beaver tale" Beaver tale is caused by the inner arch being placed too far forward causing a slight elongation of the dome. Some design a beaver tale dome shape on purpose. We can also have a combination of both if we are not careful with the layout. But, neither is a critical error and can be fixed. It just takes a little more time and a few more cuts .

mongota , you are doing a great job "paying it forward" ! I just want to bring out one point about the string method for future builders that may be reading this thread. You and I both used the IT on our builds. I've used the string method on lots of things for brick on horizontal planes, but never a compound curve such as the dome. (I'm glad that Hondo came up with the concept ) The string method may be close however, it's alignment with the anchor point is not the same. A properly built IT places the ray or center line at the center of the brick. Setting the brick with the string in alignment with the top of the brick places it catawampus with the center line of the dome. When an IT is built catawampus that can cause an offset or lip on each course that compounds with each couurse.

[mongota]

Exactly what Mark wrote.

Make the repair as you go, and correct with the next course(s) to bring it all back together as intended. .

It's likely no one will ever see it, but if any friend or family member goes to the trouble of laying on their back and shimmying their head in to the oven so they can point out the repair? Well, then by going to all that effot I suppose they earned the right to needle you a bit. But as the builder of the oven and head pizza chef, you also earn the right to never feed them another slice!

[MarkJerling]

Glad to hear. I suspect it happened from systematic use of less mortar across one or more courses. #use_an_IT

I was surprised and perplexed that my courses dipped down to the dome, but looking back at the photos I can see what happened: It looks like I altered the dome shape to marry up with the door arch. Anyway, in the end it all worked out! (Although mine's courses are not, of course, nearly as tidy as most ovens posted here! But then, it was all secondhand bricks)

You can see how the courses "dip down" on these images. And, yes I know - I should have used an IT!

[Michael Thomas]

it's made absolutely no difference to the strength of the dome.

Glad to hear. I suspect it happened from systematic use of less mortar across one or more courses. #use_an_IT

[MarkJerling]

I had the exact same problem with my oven so I simply continued those courses through onto the door arch and fixed it with a triangular wedge before the next (correct) course. It's not visible, of course, unless you stick your head in the oven and it's made absolutely no difference to the strength of the dome.

[Michael Thomas]

Michal, your build is coming along quite well, even more so for not using an IT.

With subsequent courses, just make sure the plane of the top of the brick follows the angle of the string. You are right, as you go higher, things sort of happen faster. You can probably correct that in the next ring. You may have a bit of lippage with the inside edges of that next course where you make the correction, and lippage is fine. If the lippage bothers you, you can grind it away. But from then to the plug, all will be well.

So I adjusted this issue just fine. I have some lippage but not super bothered by it. I grinded down one larger lippage on the first day I laid brick and it seems to look ok right now. However, today I discovered an issue.

Since you are not using an IT, be VERY ATTENTIVE when you cover the arch. As you transition from building on your regular course of rings where the bricks are all the same elevation, to covering the arch where the slope of the arch changes what you are building upon, it's pretty easy to allow the covering brick to slump a bit here or climb a bit there. More common is the slump (arch droop). You can use a measuring stick held vertically from the floor to make sure that the top inside corner of the arch covering bricks are the same height as the other bricks in that ring, all while using your string to make sure the top surface of the covering brick is still in plane with the tightly pulled string.

Thanks for this. From your tip, I started noticing what was happening half way through today's second course. I had suspicions of it in lower courses and checked that my course was level across and they were only slightly off so I thought NBD. But after laying several more courses, I noticed that the right side on today's course is lower than the left (for the same course!). See attached. The difference is almost an inch. : / disappointing

My solution will be to cut a tapered layer above the arch paired with another tapered layer of bricks to close the top most course in the photo. This should reduce this issue for the next course to a point where mortar can be my "corrective friend" as you put it Thoughts? (I mean, other than I totally should have used the IT!! Lesson learned). My assessment is that this will slow me down but not break my oven. Is that right?

Michael

[mongota]

Michal, your build is coming along quite well, even more so for not using an IT.

With subsequent courses, just make sure the plane of the top of the brick follows the angle of the string. You are right, as you go higher, things sort of happen faster. You can probably correct that in the next ring. You may have a bit of lippage with the inside edges of that next course where you make the correction, and lippage is fine. If the lippage bothers you, you can grind it away. But from then to the plug, all will be well.

Since you are not using an IT, be VERY ATTENTIVE when you cover the arch. As you transition from building on your regular course of rings where the bricks are all the same elevation, to covering the arch where the slope of the arch changes what you are building upon, it's pretty easy to allow the covering brick to slump a bit here or climb a bit there. More common is the slump (arch droop). You can use a measuring stick held vertically from the floor to make sure that the top inside corner of the arch covering bricks are the same height as the other bricks in that ring, all while using your string to make sure the top surface of the covering brick is still in plane with the tightly pulled string.

Mortar joints can be your corrective friend. lol

Keep up the fine work.

[Baza]

All your help is invaluable! I appreciate your posting so frequently and timely. If no one has said it, its your attention (and Gulf and @UtahBeehiverthat is making pizza ovens built correctly across this form! ( and that is a point I'm not exaggerating :P)

Michael Thomas gotta say I agree with you COMPLETELY! These folks are titans of support, help and kindness! Wealth of info and loads of experience.
Could not have come this far without them!
Good of you to say.

Barry
PS - your build is looking GREAT!

[Michael Thomas]

Are you setting those with your IT?

I'm not using an IT but a string fixed to the center of the oven at ground level. I had a mason convince me to use the string but he's an expert and is probably a wizard that doesn't need an IT :P

With your mortar being fresh, you could pop those and reset them. If you have fat mortar joints on the outside of your dome, all you have to do is tap that top outside edge a bit lower lower to bring the upper surface of the brick back in to plane with the string/IT. Do try to learn WHY they are not properly aligned so you can correct in future courses.

Thats a good idea, thanks. I'll investigate and fix

If that ring is complete by the time you read this, you can make adjustments in subsequent courses to get back in to alignment. You might have a little lippage with the interior faces being out of plane here and there, but that won't affect oven performance. Please don't lose sight of the fact that even if your brickwork is off a bit here and a smidge there, your oven WILL cook! lol

Ok I'll have to do that since I have to leave the house for a while. Really glad to hear its not going to fall over! (I realize thats a paranoid thought but working from that evaluation, I'm sure I'll get this thing together!, although not a comfortable base to work from haha).


All your help is invaluable! I appreciate your posting so frequently and timely. If no one has said it, its your attention (and Gulf and @UtahBeehiverthat is making pizza ovens built correctly across this form! ( and that is a point I'm not exaggerating :P)


Michael

[mongota]

Are you setting those with your IT? That's the beauty of the IT, it keeps the top surface of each brick in plane with a ray (or string) emanating from the center point of the dome floor, as well as keeping the inside-the-dome face of the brick properly aligned to be part of the smooth surface of the interior sphere.

With your mortar being fresh, you could pop those and reset them. If you have fat mortar joints on the outside of your dome, all you have to do is tap that top outside edge a bit lower lower to bring the upper surface of the brick back in to plane with the string/IT. Do try to learn WHY they are not properly aligned so you can correct in future courses.

If that ring is complete by the time you read this, you can make adjustments in subsequent courses to get back in to alignment. You might have a little lippage with the interior faces being out of plane here and there, but that won't affect oven performance.

Please don't lose sight of the fact that even if your brickwork is off a bit here and a smidge there, your oven WILL cook! lol

[Gulf]

I’m guessing that you don’t have an IT. If you lower the string to exactly the center of the brick, that will give you a better idea of The slope which the brick should be laid. A properly built IT takes all the guess work out.

[Michael Thomas]

Hi mongota and Gulf

Do you think this is an issue? I’m towards the upper courses now and I’m wondering if I have to start correcting with mortar. I can’t think of a deal breaker issue if the dome flattens earlier than a perfect half dome. Thoughts? Should I cut my next course of bricks to adjust?

[mongota]

Wow. Looks terrific!

[Michael Thomas]

went decent, thanks Gulf and mongota! The suggestion to avoid the mortar joint creep was really helpful. I marked on the form/template and that kept me in line. I don't think I would have thought of that hadn't you mentioned it.

[mongota]

It should work fine, Michael.

I agree with Joe regarding the IT. Because of how I made my IT, I could use it to lay out the cuts for those arch bricks. Some folks have ITs that are too bulky or non-maneuverable, they can be difficult to transfer lines from the IT to the bricks.

When you set those bricks, you'll use the IT. Your IT will set those bricks just like any other, the tapered face of each arch brick should be a plane in line with a line radiating from the center point of your dome floor.

Since the arch bricks are are all cut in advance, one thing to watch when you mortar them up is to make sure your mortar joints don't push the bricks from their intended spots. That you don't suffer mortar joint creep and your TDC brick ends up being at 1 o'clock or 11 o'clock on the arch template, instead of TDC at 12 o'clock. Keep track of your layout marks on the template and adjust as necessary.

Congrats on the progress. Getting the arch done is nice. Covering the arch with no droop will be even nicer!