BrritSki's Build in Italy

[christo]

Re: BrritSki's Build in Italy

Looks good. I was really excited when my oven got to that stage.

Any particular reason why you didn't go with the herringbone pattern for the floor? I got advice that it helps to prevent the pizza peel from hanging on a brick edge and so far it's working very well for me.

Christo

[BrritSki]

Re: BrritSki's Build in Italy

I would have gone for a herringbone with square bricks, but a rectangular herringbone doesn't look right to me - I am a genuine Virgo and very obsessive about detail as my wife can confirm

I understand about the peel catching an edge and I've been very careful to ensure there are no raised front edges that will cause a problem.

As you say, this is the really exciting stage.

Ciao Rog

[james]

Re: BrritSki's Build in Italy

Ciao Rog,

Your vermiculite layer came out very smooth. Nice. How would you describe the Italian vermiculite? Was it fine, or a little bit lit porridge (Scottish Oats?)?

You oven will be fine using Portland cement, rather than refractory cement. That layer just won't get that hot.

Keep going.

How's the weather when it isn't raining?
James

[BrritSki]

Re: BrritSki's Build in Italy

Good day today - floor laid and first course laid out dry ready for mortar tomorrow.

I had real problems with the paste - I used the mud from brick-cutting mixed with very fine sand and some pounded brick offcuts. It was very hard to mix (separated out into water and solid fireclay/sand layers) so maybe I got the proportions wrong, or maybe it was all too fine.

When I spread it out on the concrete floor I couldn't get a nice comb effect either - it was either too dry and I scraped it all off or it was too wet and it just settled back into a level layer of gloop. I eventually just got it to about the right thickness and then put zigzag lines into it with the edge of the trowel to allow for some tamping down with the rubber persuader (aka mallet). It's not perfect, but it's close enough - level and flat with no raised edges to catch the peel.

The two bricks on end define the inner entrance, they are 18" apart and 11" high, but there will be a very gentle 1/2 brick deep arch to raise the height to 12" in the centre.

The rest of the oven opening will be 2 bricks deep, set back an inch to give a reveal. The outer entrance will be 1/2 brick deep and will have the same arch height as the inner entrance as I figure I can tilt the fire-door forward to clear the front arch as it goes in or out.

This will leave an inner slot 1/2 brick deep (plus mortar) which will taper up into the chimney.

Ciao Rog

[BrritSki]

Re: BrritSki's Build in Italy

Your vermiculite layer came out very smooth. Nice. How would you describe the Italian vermiculite? Was it fine, or a little bit lit porridge (Scottish Oats?)?

Vermiculite was probably a little bigger than oats, but not by much.

How's the weather when it isn't raining?

Haven't had rain for some time now. Nice and hot, but not too bad under the tarpaulin shade and with a breeze most of the day. Plus when it's too much I just go and take an outdoor shower and jump in the pool

Ciao Rog

[BrritSki]

Re: BrritSki's Build in Italy

More progress today, slow but sure.

First a bit of carpentry to make the wooden former that will support the entrance arch so that I had something to hold the entrance uprights in place. Then I made a load of 7.5 degree wedges.

First course was then mortared into place, but this was my first foray into using refractory mortar and following the instructions on the packet for the amount of water it turned out much too sloppy. Never mind, it wasn't too bad to work with for that first course.

Once that had set a bit I then placed the second course and mixed up some more mortar. I held off on the water this time and got a much more usable mix.

With the excess mortar I "plastered" the left hand side of the dome, but didn't have enough mortar left over to do the right hand side. Is it really necessary to plaster over everything - does it add significantly to the strength of the dome - or is a minimal mortar approach better ?

Ciao Rog

[BrritSki]

Re: BrritSki's Build in Italy

Completed course 3 on Saturday and then more progress today with course 4 done and also the inner entrance arch.

Very lucky on that - I cut the corners off the 2 upright bricks just by eye and the arch then took 7 bricks exactly. It even stayed in place dry when I took the form away, but I put it back before mortaring up and will leave it there for a few days.

At least 1 more course this afternoon, but can't decide whether to start bevelling the brick edges or not on this course or the next. Will go and have another look and a measure and see what is best.

I did a quick spreadsheet to calculate the diameters (centimetres) of the top of each new course, but my measurements show that my actual diameters are less than calculated. Are my calculations wrong (reduction = sine of angle * brick height), or (more likely), are my wedges a tad more than 7.5 degrees ?

Brick height 5.8 Radius Crs Diam. Measured
Angle Radians Redctn 1 95.0
07.5 0.13089969 0.76 2 93.5
15.0 0.26179939 1.50 3 90.5 89.5
22.5 0.39269908 2.22 4 86.0 84.5
30.0 0.52359878 2.90 5 80.2
37.5 0.65449847 3.53 6 73.2
45.0 0.78539816 4.10 7 65.0
52.5 0.91629786 4.60 8 55.8
60.0 1.04719755 5.02 9 45.7
67.5 1.17809725 5.36 10 35.0
75.0 1.30899694 5.60 11 23.8
82.5 1.43989663 5.75 12 12.3
90.0 1.57079633 5.80 13 0.7


Ciao Rog

[BrritSki]

Re: BrritSki's Build in Italy

Just completed the 5th course and decided to cut bevels on alternate bricks. Seems to work OK.

Any reason why I shouldn't continue doing this - seems too easy ???

[BrritSki]

Re: BrritSki's Build in Italy

Yesterday wasn't great - 6th course went up OK, but then it was the dreaded 7th course and the bricks don't stay in place on the wooden wedges at that angle (surprise surprise !).

Played around with different things and got a couple of bricks to stay in place and started work on a polystyrene form, but had lots of interruptions (including Olympics - go Team GB!) and had to stop early as we were going out, so I didn't get it finished.

Today was a beach and shopping morning, and then lots of emails to deal with - organising a wedding in another country is fun - so another late start, but decided to try a different approach and it works.

As I'm sure all you experienced builders know (and it IS mentioned in the plans and lots of threads and I should have remembered from my brick-laying course), having damp bricks and sloppier mortar really helps, so I used a little hand sprayer on each brick and it's destination first, and then mortared them all in place individually, just using a thick stand-alone wooden form to hold it in place for a minute or so for the mortar to "grab".

Worked a treat, but ran out of cut bricks so closed down for the day, but when I measured the angle of the bricks on the 7th course they're almost exactly 45 degrees as they should be - hurrah !

Tomorrow should be an early start and I aim to finish the 7th course, finish the former and get a couple more courses done with the aim of finishing on Friday.

Wish me luck... Ciao Rog

[egalecki]

Re: BrritSki's Build in Italy

It's looking very good. When my courses got high enough to want to slip forward, I used an L shaped bracket, string and a brick- the bracket went over the edge of the brick, tied to the string, and the string was tied to a loose brick at the base of the oven. This held the newly mortared brick in place long enough to set, and then I moved it to another brick. I had three of these set up and it was plenty good enough until I got to the really vertical places, then I switched to using bamboo sticks to prop up the bricks.

[BrritSki]

Re: BrritSki's Build in Italy

It's looking very good. When my courses got high enough to want to slip forward, I used an L shaped bracket, string and a brick- the bracket went over the edge of the brick, tied to the string, and the string was tied to a loose brick at the base of the oven. This held the newly mortared brick in place long enough to set, and then I moved it to another brick. I had three of these set up and it was plenty good enough until I got to the really vertical places, then I switched to using bamboo sticks to prop up the bricks.

Hmm, sounds like a good idea, but I've got most of the polystyrene former cut out now and only need to tape it together...

Maybe next time

Ciao Rog

[james]

Re: BrritSki's Build in Italy

Way to go Rog,

Keeping your brick and mortar wet/damp is so important. Are you dunking them in the water as you work?

How about that Brit Olympic team -- ahead of Italy, France and Germany. Excellent.

James

[egalecki]

Re: BrritSki's Build in Italy

sorry, meant to attach a picture. I swiped the idea from someone else, can't remember who. He used a different shape clip, but the idea works well. Just don't trip on the brick counterweight!

[egalecki]

Re: BrritSki's Build in Italy

I was particularly impressed with the woman who was an alternate on the British equestrian team's performance in the eventing! What a wonderful job she did!

[Les]

Re: BrritSki's Build in Italy

sorry, meant to attach a picture. I swiped the idea from someone else, can't remember who. He used a different shape clip, but the idea works well. Just don't trip on the brick counterweight!

Since I wasn?t using mortar to hold the bricks in place, I used hot melt glue. But hey, it was good enough to hold them to the last course.

Les...