38" Pompeii build

[MarkJerling]

Welcome aboard Frenchie! Looking good so far.

[Frenchie]

I have finally cut my templates for the fibreboard and brick floor, and have marked out on my slab where the oven will go and on the fibreboard marked up the cuts.

some questions when thinking about next steps;

1) what is the best way to cut calsil (1”)? I have a jigsaw and all the PPE but is that too aggressive

2) is it an inconvenience or a showstopper if the calsil gets wet during construction? It might take several more weeks and have only a tarp to cover things

3) is there anything between the floor bricks and the calsil? A screeded layer of sand&fireclay?

4) has anyone experience using the Vitcas range of materials for cement & mortar - are they any good? If not what would be a good choice in the UK?

5) for cutting the firebricks, will 9” grinder do for the more detailed cuts? I plan to bolster the halves for the sake of my neighbours. On that note, are there any great tricks to know for bolstering fire bricks?

thank-you, hope to provide some picture updates for you once some more tangible progress is made!

[Frenchie]

Made some progress yesterday now the rain and wind finally cleared off!

Cut the floor insulation - in the end I used a 6" drywall jabsaw which was handy. My jigsaw shoe has gone out of alignment so it makes a mess of things. I'm very glad to have this job out the way, the cleanup was arduous and it means I can get on with laying brick!

Mocked up the floor - I laid out the bricks on my template in a herringbone and marked the centre of the pattern (the true centre of a herringbone goes between the two lines of points, and not on the points themselves). Then I drilled and plugged the centre brick to mount the IT and scribed the outside diameter of the floor (initially I got the dimension incorrect, so you'll see two diameters - ill be cutting to the inside one).

Then I put my mosaic tiles on the oven floor where I had marked out the outline of the oven. Some of the tiles had gotten wet over the winter and the backing mesh has discoloured - this won't matter as they just raise the calsil off the slab and provide some drainage channels.

After that I laid the calsil sheets (3x 1" thick layers) on the tiles and marked out the centre of the oven (relative to the foundation) on the calsil. I cut the calsil about 5-10mm in any dimension larger than it needs to be to account for positional tolerance on the foundation.

Finally I transferred the bricks from the mock-up on the template to the calsil, starting with the centremost brick (with IT attachments) and working along the centreline initially.
I think, theoretically the oven and insulation should now be centred on the slab per design.

I had a go at bolstering some bricks. Made a quick jig using scrap materials as I will be cutting a lot of halves, scribed a line around 4 sides of the brick and tapped each side before giving a good hard crack to break the brick on one of the wide sides. This worked remarkably well so I am happy to continue bolstering the dome bricks.

For the neater cuts, around the perimeter of the floor and for the arch bricks, I will use the 9" grinder with the 2mm thick diamond blade.

Given autumn is closing in on us, need to get a move on here.

Open to suggestions! thanks all

[mongota]

These projects do get put on the back burner sometimes, my own did when I had to move halfway across the country for an extended bit to take care of my in-laws.

Glad to see you back at it.

Step-by-step.

[Frenchie]

These projects do get put on the back burner sometimes, my own did when I had to move halfway across the country for an extended bit to take care of my in-laws.

Glad to see you back at it.

Step-by-step.

Thanks mongota, step-by-step as you say. Now I'm getting on with things I am reminded why it was such slow going last time - doing anything for the first time comes with a degree of trepidation, and all of this is new to me!

[Frenchie]

Cut the floor bricks at the weekend, and arranged some half bricks to see first hand the gaps formed by not tapering.
I also started on the first level of arch brick - I have tapered bricks to form the arches so those will be some interesting cuts with the 9" grinder...!
I really see the merit of a wet saw now, and I am considering renting one for a few weeks.

Next step is to position the inner arch form and mark its position on the floor (I may even screw it down through the shims). Then I will re-cut floor brick adjacent to the left had arch brick as something has gone out of whack (grinder is an agricultural cutting method especially for internal angle cuts!) before starting on the inner arch.

I have modelled the semi-circular arch intersection with the dome several times and cant get away from concluding that my arch bricks are all identical. Is this a function of a semi-circular arch or is it some miracle of geometry? In line with all other advice on this forum I was expecting the tapered arch bricks to differ as we go up in height.

[Frenchie]

Progress has been slow, my temporary shelter blew away in a storm and the insulation board got soaked.
I presume the board will be fine (calsil) so I’m cracking on regardless.

bottom course of dome is mostly down and have nearly finished cutting my inner arch bricks. (I wish I had a proper wet saw)

all the bricks are the same, per the sketchup model. I presume this is a function of a semi-circular arch intersecting a hemispherical dome.

Skill level is zero, it is not beautiful work, but it will cook pizza. At this stage I’m just enjoying it and not stressing over perfection (or anything close)

[UtahBeehiver]

For not having a wet saw, you floor bricks look great. Search for "taper inner arch" on the blog, there are dozens of examples of arch and dome interface. It is the best way to form a effective tie of inner arch and dome.

[JRPizza]

Looking good! I had a similar shelter malfunction and got my floor bricks and insulation soaked. After that they were covered for months but still held lots of water till I did my slow drying fires.

[david s]

Your build is going exceptionally well. the elevated insulation will help the drying process. If you can, expose the project to sun and wind to allow ir to do nost of the drying for you. Failing that perhaps set up a fan.

Chexk out my insulation drying experiment here.

https://community.fornobravo.com/for...098#post458098

[Frenchie]

Slowly slowly slowly, progress is made. Rarely get the chance to do work and manage around 1 course of bricks per day when I do!
enjoying the process, aiming to close the dome by end of September (yes, this year)

[Frenchie]

Hi there, I have a materials question; could anyone recommend a material to form the outer arch slab?

the floor, inner arch and dome are built on 3” calsil which rests on mosaic tiles on the main suspended slab. I will form a second slab outside the inner arch on which the outer arch will be built.
there needs to be reasonable compressive strength and some heat resistance. This material should also bond (I will score some shear keys into the existing slab) to the slab so I don’t want to just build it out of dry firebrick, although I have plenty offcuts which can be used to bulk out the mix. Would a standard concrete be sufficient for this application, on the basis it receives no direct heat?

Thanks!