Help!!!

[wotavidone]

About to start an oven for a mate. The best we can find is 50mm/2 inch thick bricks. There is just nothing else around here in town.
Plan is to do a 36inch/900m oven. Obviously, 2 inch thick bricks equals lots of courses of bricks, which we can handle as we have a decent diamond saw on loan, although I know it's a lot of mortar too. Or is it?
The dome will be 4 inches/half a brick thick.

The question is will a 2 inch thick floor be good enough?
I see three options:
1) Use the 2 inch/50mm floor and be happy
2) Bed the 2 inch bricks on an inch of homebrew to get some more thermal mass
3) Might be able to bludge some 3 inch bricks off the last mate I assisted to build.
Opinions urgently needed.

[hubert_s]

Re: Help!!!

For what it's worth, the Artigiano oven from FB has a 2" cooking floor.

I built a 36" dome out of 2 1/4" thick bricks. I don't think it required a lot of mortar, I only used a little over half a bag of fireclay. I did use thicker brick for the oven (2 1/2"), but only because they had a smoother surface, not for the added thermal mass. I would go with option 1 and be happy.

[stonecutter]

Re: Help!!!

About to start an oven for a mate. The best we can find is 50mm/2 inch thick bricks. There is just nothing else around here in town.
Plan is to do a 36inch/900m oven. Obviously, 2 inch thick bricks equals lots of courses of bricks, which we can handle as we have a decent diamond saw on loan, although I know it's a lot of mortar too. Or is it?
The dome will be 4 inches/half a brick thick.

The question is will a 2 inch thick floor be good enough?
I see three options:
1) Use the 2 inch/50mm floor and be happy
2) Bed the 2 inch bricks on an inch of homebrew to get some more thermal mass
3) Might be able to bludge some 3 inch bricks off the last mate I assisted to build.
Opinions urgently needed.

I think you would be fine with a 2" floor, unless your friend want days of stored heat. If that is the case, I would go with option 2, but you should not apply a thin bed of straight mortar like that....it will break up and could throw the floor brick out if level. Make the bed mortar more like a concrete...you could use crushed brick as aggregate, and use wire reinforcement.

[wotavidone]

Re: Help!!!

Thanks guys.
Discussing this with people who have "been there, done that" makes it easier.
In the morning, I'll ask my mate who has a few left over 3 inch bricks if he can spare a few.
If not, I'll see if I can get some 1/4 inch aggregate to make an inch thick concrete layer under the bricks. If not, 2 inches sit is.
Stonecutter, I was at a newer sand yard today, he had some nice coarse washed sand for making mortar for big gaps. He had some quartz rock about 1/4 inch, very smooth like river rocks, do you think it would suffice as the coarse aggregate in a concrete mix?

[stonecutter]

Re: Help!!!

Thanks guys.
Discussing this with people who have "been there, done that" makes it easier.
In the morning, I'll ask my mate who has a few left over 3 inch bricks if he can spare a few.
If not, I'll see if I can get some 1/4 inch aggregate to make an inch thick concrete layer under the bricks. If not, 2 inches sit is.
Stonecutter, I was at a newer sand yard today and he had some quartz rock about 1/4 inch, very smooth like river rocks, do you think it would suffice as the coarse aggregate in a concrete mix?

If it had been crushed aggregate, I think it would be ok, but not rounded. Any round aggregate.. whether it's sand or large graded..makes very weak concrete. I would pass on it. If you can get ahold on some busted up brick, I feel that would be your best option...and it's easy to break down, and very inexpensive.

[UtahBeehiver]

Re: Help!!!

Option 4, if he wants thermal mass for cooking, two layers of 2" bricks, although I know how expensive your bricks are there. Maybe some solid reds under the 2" fire brick, just a thought.

[cobblerdave]

Re: Help!!!

G'day
2 inch brick has its advantages. I helped with a pressed clay paver build with minimal cuts. Inside the dome was pretty smooth because of the smaller size. Instead of just laying them all flat 1/3 of the way up the dome make a layer of the bricks on there edge makes a good contrast. The top of that dome was a bit harder going to 1/4s made for a lot of mortar but looked good from inside.
The pavers made a more pleasing arch too. Having thinner bricks means more units to spread the mortar gape over, each gapes smaller so its more pleasing to the eye, and all with minimal cuts.
Regards dave

[wotavidone]

Re: Help!!!

Thanks Dave.
So just cut em in half and lay them, and when the gape starts getting a little too big go to thirds, then quarters?
The pressed clay pavers have very smooth surfaces. No issues with mortar adhesion?

General advice seems to be that a decent job can be done this way.

Staring to sympathise with Stonecutter. It can be a little nerve wracking when the job is for someone else.

P.S. Did you use just 2 inches on the floor?
P.P.S. what you doin' surfing the net at 5:44 am?

[cobblerdave]

Re: Help!!!

G'day mick
Sorry for the late reply as you have said ,its a long day sometimes..
Yes I've been up and about since early.
As for the pavers being smooth, the ones I have struck, pressed clay , have a smooth surface but have a textured ... I suppose sub surface which has a grip to the mortar.
Not a fancy mortar either just a home-brew mix using brickies sand reclaimed from a building site with a couple of six packs.
As for 1/2 1/3 and 1/4s not really, it was more 1/2s 1/3s and 2/3s as you get smaller those 2/3 bridge the gape better. Easy not to get the mortar gapes to line up with those sizes.
I learnt a good trick with this built I helped with. As he had only a 8 in grinder a truly scary tool,turn it on and it moved you 2 to the right you would not dare take 2 hands of it. As a result most of the cuts were pure " brick bulster"
A sand bag on a slab of ply on a pair of saw horses made it easy and was much easier on the back.
Hope something might help
Regards dave
Ps yes the floor was 2 ins, and it cooked a mean pizza. And a roast next day.don't know how how it's going as it headed down south in a car trailer a year ago ...

[wotavidone]

Re: Help!!!

Ended up bedding the 50mm bricks on a 7 or 8mm layer of 3 parts sand, 2 parts clay.
Arch nearly finished, 4 courses of brick laid.
Had lots of different brands of paver. They seem to take two forms. The first are a quite uniform colour right through the brick, with bits of crushed brick grog showing when the are cut.
Heating a half brick on my mates 4 ring crab cooker for an hour, flicking water on the hot brick, then letting it cool resulted in an unchanged brick that couldn't be smashed on the edge of his big steel workbench.

The second sort of brick has an oval of black "uncooked" clay in the middle of the cut surface. These bricks will end up paving his bird cages, as when we repeated the heat 'em, splash 'em with water, bash them on the edge of a 10 mm steel workbench, they smashed easily.
It looks as though these are fired just enough to develop the colour on the outside, but not fuse the clay right through.