42" Pompeii Oven in Virginia

[mirassou]

Re: 42" Pompeii Oven in Virginia

Oh cool! I'll try that this afternoon!

[stonecutter]

Re: 42" Pompeii Oven in Virginia

Thanks Faith! I've already lost some pounds Someone recently posted a link to a video of some folks building a brick ceiling. The mortar looked watery, but the bricks just held with no other support! I wonder what the difference is in the bucket mixture vs. heat stop made at home.

Was that video tilted "Boveda catalana"? (catalan vault) I have seen that one or many more like it. Builders don't typically use centering for cohesive arch construction. If what you saw had multiple layers, it is a timbrel vault...the one Guastavino is famous for. The first layer in a timbrel vault is built using clay tile and gypsum for mortar.

I'm pretty sure the video you saw is of cross (groin) vault construction using handmade brick....what they are using is lime mortar, and it is loose like that because the bricks suck the moisture out of the brick very fast...as you probably noticed. No refractory quality at all.

[mirassou]

Re: 42" Pompeii Oven in Virginia

That's it! There's certainly a "wow" factor there.

[stonecutter]

Re: 42" Pompeii Oven in Virginia

I looked up some info I have and sometimes there is portland added to the building mix of those vaults. The water content of the mix definitely has to do with the porosity of the brick....it mechanically bonds in less than 30 seconds.

Timbrel or a ribbed cross vault is in my very near future.

[mirassou]

Re: 42" Pompeii Oven in Virginia

It's just amazing...I'm still stuck on the difference between cement and mortar LOL.

[mirassou]

Re: 42" Pompeii Oven in Virginia

Finished course 9 today, in addition to the outer arch...it's still standing!

[stonecutter]

Re: 42" Pompeii Oven in Virginia

..I'm still stuck on the difference between cement and mortar

Cement is a general term for Portland Cement powder.

Cement (Portland) is used as a component of mortar powder. Combined with various amounts of lime, you get types M,N,S,O mortar. Not all mortar used for unit masonry contains Portland though, such as Lime, gypsum or clay mortar.

Concrete has Portland cement as the binder, aggregate and sand.

[mirassou]

Re: 42" Pompeii Oven in Virginia

I've been attempting to get some consistency between batches of mortar and it's very difficult due to weather conditions and the level of moisture in the bricks. deejayoh commented that he just used the IT for the entire dome. I was able to do this on course 9 with one batch, about a half dozen bricks. It seems like there's a sweet spot with moisture content of the mortar vs. moisture content of the brick...I just find it difficult to achieve.

[mirassou]

Re: 42" Pompeii Oven in Virginia

Took a work break, but started course 10 today and cut a few more bricks for the vent transition. I didn't realize when someone mentioned it, but I had a case of the dreaded droop at the inner arch transition. I cut some slices and mortared them in to fix it...I may have to do a few more after course 10.

My carpenter emailed me as he is short on work, so I may cheat and have him do the framing for the enclosure

[mirassou]

Re: 42" Pompeii Oven in Virginia

Finished course 10 and 11 and started course 12 today. Also started working on shaping bricks to form a level surface to hold the chimney flue. I'm thinking now that I won't need buttressing on the arch sides, as half the weight will be supported by the inner arch/dome, and I'm going to frame Durock 2" around the flue and fill the cavity with vermiculite. Where it pops out of the roof, I'll use either stucco or brick veneer.

Looks like the vent opening will be something like 11x12.

[mirassou]

Re: 42" Pompeii Oven in Virginia

Oh, and starting course 12, I'm still using the IT and not using the exercise ball yet....going to see how far I can go. I figure cutting bricks for the vent transition to the chimney and alternating mortaring between the courses and the transition permits the vertical brick to set before mortaring the next one

[mirassou]

Re: 42" Pompeii Oven in Virginia

The only problem is that the final course layout is out of round, due to errors in angles. It probably won't look pretty, but it'll get done

[cobblerdave]

Re: 42" Pompeii Oven in Virginia

Oh, and starting course 12, I'm still using the IT and not using the exercise ball yet....going to see how far I can go. I figure cutting bricks for the vent transition to the chimney and alternating mortaring between the courses and the transition permits the vertical brick to set before mortaring the next one

Gudday
That brilliant ! Alternate between the entrance and the dome. No wasted time no wasted mortar.
Regards davr

[Greenman]

Re: 42" Pompeii Oven in Virginia

If you are determined you will get right through the dome with the IT. With the benefit of various bits to hold it together until the mortar goes off. I didn't use forms and it worked out fine.

All about personal preferences. Push the envelope.

[mirassou]

Re: 42" Pompeii Oven in Virginia

Just a few more bricks to close the dome. I'm still using the IT, switching back and forth between the vent transition and the dome. I don't have the angles, so I'm going to cut triangles to fit between bricks in the last course before the final key stones. Can't wait to finish the dome and start the first curing fire!