Simple Q's

[Sidcup1]

I have built the foundation and stand for a 42" Tuscan oven.

Just some quick Q's before starting hearth and oven build.

I intend to cast a 3" hearth, on this place 3" of ceramic fibreboard and start with a soldier course of bricks.

- The ceramic board is just placed on, and not fixed to hearth ?

- The firebrick floor can be just placed on the fibreboard, and not mortared or bedded on sand ?

- Do the soldiers get mortared to the ceramic board, or just to each other at the sides ?

- I intend to cut the firebrick floor to fit inside the oven dome. Should an expansion gap be left between the floor and the soldiers ?

- I want to mix my own home brew mortar for the dome. Would this enable the mortared gaps between bricks to be larger? If so....what's the maximum width of mortar between bricks ?

- What is the point of cutting and shaping dome bricks. You use less mortar, and it looks neater, but are there any other advantages other than cosmetic ?

Hope to get some pics posted soon.

Thanks

Jimbo

[boerwarrior]

Re: Simple Q's

Hi Jimbo

Welcome! I see that no-one has replied to your post yet so I will weigh in!

- Yes, the ceramic board is placed on the hearth - trust me, with the weight of the oven it is not going anywhere!
- The floor can be placed directly on the board or bedded on a THIN layer of sand. The sand is simply for leveling. If you don't need sand, even better (I have no sand between my fire brick and ceramic board). Don't try and mortar anything to the board - the board will suck all the moisture out of the mortar. Not needed anyway
- as above, soldiers are placed loose on the board and only mortared to each other
- Lots of discussion on this forum about expansion joints... I left about 2 mm between my floor and wall. After a few pizza's the gaps will fill up with ash. So sure, leave a small gap but it doesn't have to be large.
- Not sure why home-brew would allow for bigger mortar gaps? Most people here (me included) aim to have as little mortar facing the interior of the oven as possible. One reason is that no matter how good your mortar is, some of it will break down eventually. One expert here even built an oven with NO mortar! My coaching would be to have as little mortar facing inward as possible.
- as above, cutting bricks reduces the amount of inward facing mortar. Other than that, it's also cosmetic as you suggest.

Take a look at the multitude of pictures and you will get more ideas. There is no such thing as a 'perfect' oven. I made a lot of 'mistakes' with my build and yet my oven works fantastically!!

Good luck and keep the questions and pictures coming

Neil

[Sidcup1]

Re: Simple Q's

Thanks For your reply Neil.

That's cleared most things up. Just a small point so I am sure I understand you.....do you mean cutting bricks reduces mortar on the outside of the dome? Wouldn't the bricks almost touch on the inside of the dome whether they were shaped or not ? Not being pernickety....just want to make sure I understand correctly.

Also....regarding the opening of the oven. A 20" wide and 12.5 " high opening is recommended by the FB instructions. Most widen to the mouth of the oven by the landing. Is there a correct amount of widening I should aim for? I was thinking of a widening to 25 5/8".

Cheers

Jimbo

[UtahBeehiver]

Re: Simple Q's

Jimbo,

Looks like Niel answered most of your questions. Some cutting of the dome bricks will be necessary in you want tight inner face joints and well as avoiding what we call the inverted V joint. Look at DJs dome calculator which does the figuring for you. One more addition to the gap between the dome, if you choose this route, run a piece of duct tape over the gap during your build to keep errant mortar from dropping in and defeating the purpose of the gap. If you are building an enclosure around the oven, then you may be able to place the soldier course right on your floor brick thus no gap and saving yourself a bunch of tedious floor cuts.

[GianniFocaccia]

Re: Simple Q's

If you like the look of a soldier, by all means go with them. You really don't need a soldier course and there are benefits to starting with a horizontal first course (easier to mortar, benefits of gravity, improved line of thrust). I believe that the Italian ovens (to this day) are built with speed in mind, and I was the exact opposite: put as much craftsmanship into my oven as possible since I only got to build it once, and I'm the one that has to look at it for as long as I operate it.

If you taper your bricks from front to back you will end up with a consistent mortar gap between courses. Yes, this reduces the required amount of mortar but is another step in fitting your bricks. The reason I did this was to reduce the amount of cracking that comes from larger amounts of mortar when it dries.

Like the height, the width of the oven opening controls the way the oven breathes, heats up, and retains heat. I may be mistaken, but I believe a 25"W opening is too wide for a 42" oven. (My 39" oven opening width was designed with a 21"W opening, but I changed it to 20" and am glad I did. Because I tapered my entryway, there is plenty of angle to get to the fire and food inside. I haven't yet found anything so wide that I can't fit it through the opening.