42" Pompeii at the Concrete Casa

[michaewa]

Re: 42" Pompeii at the Concrete Casa

Jon - Yes, that is a piece of cement board. It breaks easily when scored, but I do need to score it into sections before I get much more closed in. I'm sure it will be harder to get out than it seems.

[michaewa]

Re: 42" Pompeii at the Concrete Casa

I apologize for the cross post but I wanted to provide some photographic evidence of my crimes.

These pictures will hopefully make more clear the tie-in situation and my feared inadequate fix. I've been looking at other options since yesterday, including as as been suggested flaring these bricks back toward the arch more and 'corbelilng' them on future rows. Also, I saw another thread where two full bricks were placed to span across the arch - I like the stability of that, but I don't know if the extra weight would be a bad thing.

The first picture shows the scant bearing surface, and the second a huge nasty glob of mortar I put in there. It actually has set up quite hard and feels sturdy.

I'm just trying to determine if I'm courting disaster by continuing in this approach. Tscarborough suggested that once I close in the dome it probably wouldn't be an issue - I can see the logic from an engineering standpoint considering the inherent properties of a dome, but I'm a little nervous about having that blob fall out upon my first real fire.

Any thoughts or suggestions appreciated...I knew the tie in would be a challenge but didn't expect it to turn out quite like this.

[Alter ego]

Re: 42" Pompeii at the Concrete Casa

My bricks running into the arch were very similar to yours except I cut little pyramids of brick and mortared them in where you have all the extra mortar. My theory was that the might help to hold up the brick above. If you look at the attached pic you will see that the handle of the rubber mallet is being used to hold the section of brick in place while the mortar hardens.

I was worried if these bits of brick would stay in place but 12 or so firings of my oven and they haven't moved yet. so I think what you have done will be fine.

Paul

[michaewa]

Re: 42" Pompeii at the Concrete Casa

Paul - Thanks very much for the reply. I got a little antsy and tired of worrying about it today, so I decided to take some action.

The unfilled span was almost exactly the size of one full brick, which I took to be a sign - after all it couldn't just accidentally be that size, could it?

I angled the top of the arch to match the slope of the bottom of the brick, and put a very slight taper on the front of the brick so it laid snugly inbetween the bricks on either side.

I set the brick back about 1/2" from the inner dome wall (as defined by the other bricks) to give it more bearing surface. I think that between that extra surface area, the bricks wedged on either side, and the natural dome shape bearing down I will be ok. Even without mortar it felt soild.

Those changes will require a bit of adjustment on the next row to 'catch up' to the dome shape but at least I don't have to wake up in the middle of the night wondering how to work it out.

I'm going to let it dry for a few days before proceeding too much further.

Thanks again for the comment, and if my dome collapses I'll head to AUS and you can make me a pizza while I cry in my beer - I'll be happy to extend the same offer to you

I'll get a picture of the whole mess up soon...

[Alter ego]

Re: 42" Pompeii at the Concrete Casa

.. I'll head to AUS and you can make me a pizza while I cry in my beer...

I'm only too happy to make pizza these days as an excuse to fire up my oven.

Be reasured that the only thing that will be able to see the build inside above the arch when you have a fire going are the pizza. I have not yet heard any one of the pizzas that I have cooked complain about the quality of my brick work!

[michaewa]

Re: 42" Pompeii at the Concrete Casa

Got row six done last week and started on row 7 today. I've set the first brick repeatedly all morning, only to have the whole thing slide in when I get about three set. I've been letting them sit increasing intervals inbetween, but I'm afraid at this pace I'll be cooking pizza sometime around the next world cup.

Any tips for holding them in place? My indespensible tool works for one brick, but then when I move it to the next I start to have problems. I'm using homebrew mortar, wondering if that is less sticky than the commercial options?

[morrishuckeba]

Re: 42" Pompeii at the Concrete Casa

I think that might be your problem soaked your bricks to long. What I did was spray lightly where going to be putting the bricks. The brick that I was going to lay I put it in a bucket of water for just a few seconds. I also cut wood strips to help secure the brick until it had time to set up.

[michaewa]

Re: 42" Pompeii at the Concrete Casa

Thanks very much for the tip - I think that I'll try that tomorrow. Today I found this thread and tried that approach.

I used romex wire leftover from building our house, cut into sections and bent into a '7' shape. That worked well, and allowed me to get around the 7th course and close it in.

To give myself a head start for tomorrow I went ahead and set the first brick of course #8, and one piece of romex wasn't sufficient - I had to use two and even then it took a few tries. The first one definitely seems to be the trickiest, so I figure if I let that one set up overnight I'll at least have two surfaces for the next brick to hold onto.

Cheers!

[michaewa]

Re: 42" Pompeii at the Concrete Casa

Banner day yesterday, completed rows eight and nine.

Scraps of pex tubing worked a treat, they held the bricks in place while I worked my way around. I dropped a few things inside the dome and it was a bit like playing 'Operation' trying to remove them without knocking anything loose.

I also set the first brick of row 10 to let it cure up. I'm pretty sure that will be my last full chain, and I'll build a plug out of a few bricks mortarted together and drop it in to top it off.

Cheers and thanks to all for your input and advice!

[morrishuckeba]

Re: 42" Pompeii at the Concrete Casa

Congratulations, it is pretty neat to see that plug go in very top. I am on my fourth curing fire. I am shooting for Wednesday to have my first pizza. I only have two very small cracks in my dome so far. Tomorrow I?ll be building a pretty good-sized fire for maybe a couple hours.

[michaewa]

Re: 42" Pompeii at the Concrete Casa

Thanks! I hope to be there with you shortly...

Are you using the smallest / smaller / small / medium curing schedule from the plan? I'm on the fence about that, it seems a little unscientific to me. I've read a few suggestions on here that say to put a heat source inside the dome to get it close to 200F, and then measure the temp inside and on the outside of the dome. When they are equalized, safe to think that most of the moisture has been driven out, and that you're pretty well cured.

[morrishuckeba]

Re: 42" Pompeii at the Concrete Casa

I started out with a electric heater for a day, then a very small fire out of paper, A small wood fire, then a larger fire and so on. The outside of my dome today you could not leave your hand on it because of the heat. I think you might be right is probably as dry as It will get.

[michaewa]

Re: 42" Pompeii at the Concrete Casa

Some pics from the last few courses... I got row 10 done last night, and as soon as the keystone was in and I started cleaning the whole mess slid down about an inch. I wasn't a huge fan of starting it over, but it went much faster with the bricks already cut.

Far from perfect masonry but I can definitely live with it.

I found that using one unmodified 1/3 brick alternated with a trapezoid brick worked pretty well for the rows starting at about #7. I shaped them either with a grinder or the saw with about equal results.

I'm going to fuse together two full bricks and cut them in the shape of the hole for my keystone and close it up in the next day or so.

Cheers!

[morrishuckeba]

Re: 42" Pompeii at the Concrete Casa

Looking good, you will be having pizza soon.

[Dino_Pizza]

Re: 42" Pompeii at the Concrete Casa

I like how your trapezoidal brick pieces work too. Makes for a tight closing, especially up at the top where it's so hard. What's your final dome height? It looks nice and flat at the top where it's ready for the keystone.
Nice job,
Cheers, Dino