My brick oven

We will wait in anticipation Matthew!

Jeremy

Is it an Alan Scott or home made oven?

Jeremy

I'm a bit embarrassed on two fronts. One that it took almost exactly 10 months to post photos, and secondly that the oven still isn't finished. However the hearth is finally poured, and I'm ready to lay bricks! OK I've got to buy the firebricks and thermocouples first, but then I'm ready.

My brick oven to date, hearth slab poured, finally time for some bricks. YAH!!

This is how it all started back in Jan.

Before the hole it was an idea and a space.

With summer starting and longer evenings I'm targeting a functional oven (not finished but with a fire in it) by New Years. Wish me luck!

Matthew

if i can ask, what plan you follow with your project ?
i knew that regadless what oven i would build i would need a slab and got this done 2 months ago but i still didn't decided on specific oven designe

how do you go about getting fuel (trees?) in australia?

Great job, Matthew! Yes! We're going to see breads soon.

Time for another update on the brickoven.  I've actually got a bit further than this, I've now laid the front hearth and the 2nd and 3rd arches on the dome.  So I'm almost ready to close in the dome.  But those photos are still on the camera.  I'll download them another time.

Here's what it looked like all braced up ready for the dome to go on the walls.

 

Mocking up the first arch.

Laying the first arch.

Much to my relief it held.  it sagged slightly because I hadn't notice but the right hand side wasn't as tight to the template as it should have been, so the arch is a bit wider on the RHS than designed.  I fixed this tendency in the next 2 arches, but you'll have to wait for the photographs to prove it.

Matthew

Hi Matt,

Just curious if you're using refractory mortar?  

In fact, are those bricks used in the side and back walls, and the arch, refractory bricks? I can see the hearth constitutes refractory bricks but I can't tell if the others are.

how it all goes as well as see how it lasts over a couple of years.

I'd have thought making it in such a way to last more than one life time would be more prudent. Unless you plan on making another down the track for your children or grandchildren.

Beside that it looks like a great project and you seem to have it worked out.

Anyway, good luck with it and keep posting.

From what I've been able to find out, the refractory bricks/mortar are really only necessary for repeated and frequent temperature cycling of the walls and dome. 

I'd build for more than one lifetime in mind if I thought it likely that my children/grandchildren would be living in the same house after I die.  But here in NZ that is extremely unlikely.... 

Also the firebricks cost me approx $6.60 each, while the pavers cost me $1 each.  So their wasn't really too much consideration given to using firebricks throughout once I was confident that I didn't really need them.

Will keep posting as I go, but can't promised that it will be finished anytime soon based on experience to date

Matthew

G'day Mat,

you must have progressed further, I'm keen to see and hear how it's going.

BTW something that occured to me while looking over your photos; it appears this is being constructed in a suburban back garden, is that correct?

Did you need to get local council permission to build?
Did they stipulate any features to comply with by-laws or regs?
Will you need permission to burn?

I just got off the phone from Alan and asked him about "stretcher bond". Alan says that we need to forget everything we ever knew about the design of kilns and older style wood fired ovens (like Scotch Ovens) that use different systems. His design does not require any brick bonding. I wanted to go further with my questioning but it was late and we had talked a while. But basically...Alan does not recommend 'stretcher bond' with his ovens.

Alan was just a bit tired to go into details....but I'll try to find out more next time. He has been very busy and in particular has just imported a flour mill which will be installed in his home town of Oatlands, Tasmania. The mill will be 100% Organic and mill locally grown grain, mainland grain, and other foods as well.

I will encourage Alan to post here personally. We had a web page dedicated to Alan, similar to John Downes page, but for some reason it got left off when the site moved to the new s/w. Alan's page will be back!

Hi sorry for the belated update but March was just crazy with two birthdays and a family holiday at Easter.  So unfortunately I haven't made a whole lot of progress and haven't photographed all the progress that I have made.  Here is a bit of an update.































This is the entrance to the oven and base of the chimney starting to take shape.  The front hearth is mainly old firebricks from a friends fireplace with a few new ones "recovered" from the sides of the hearth to make up numbers.  It turns out I had the hearth about a brick wider on each side than it absolutely had to be.  The pictures below shows some detail of the brickwork.  They also show that because of how I'd laid my hearth out to avoid cutting bricks and maximise area combined with the way I designed the front I've ended up with this gap which I'll have to fill to avoid the loose insulation pouring out. My current thought is a perlite cement - insulation and soft enough to take a bit of compresion as the hearth expands.











































































Since these photos were taken I've added a fourth arch of 1/2 bricks because as I mocked up the ramp down to the door I realised that the gap was too wide.  Now I've also laid in the lintel for the door at the ratio AS specifies (63 or 66% can't remember which of the top of my head).  Next step is to ramp the dome down to the door and close it off.  Then I can build the chimney up a bit more.  I hope to get the covers off tomorrow and make some more progress.  Will get the camera out then.

Danubian,  to answer a couple of your questions.  The dome heaves as it heats so I think the arches are not tied together to provide for a bit of movement.  Also the dome is going to be surrounded by re-inforced concrete over foil (to avoid bonding to the brick) this adds mass and stabalises the walls and dome.  Finally, yes it is in a suburban backyard.  I spent a lot of time talking to the council about it and in the end I discovered that it didn't need a building permit as it wasn't big enough and wouldn't be inhabited.  The fire permit people didn't really have a rule that covered it, so the best answer I got was check whether it needs a building consent and then build it.  Once it's built we'll come and check it out.  I haven't decided yet whether I'm going to be brave enough to tell them when it's finished. 

I'm getting a bit excited now it's starting to look a bit more like an oven but also a bit depressed about how long it's taking and how much longer it will be before I get to use it.  Too many weekend family commitments.

Matthew

Thanks for the compliments Danubian.  Yes the slot is for the ashes.  Scrape them out of the oven and let them fall down the slot into a big metal bin that will be underneath.

Matthew

Well with last weekend being ANZAC day and a weekend of pretty good autumn weather I made some more progress on my oven.  Unfortunately I can't get the photos into the gallery. 

However, the baking chamber is now completely closed in and the chimney arch is complete.  Next step is to build the chimney up a bit more.

Matthew

Well the photos are up now (thanks Maedi ).































At the start of the weekend the transition had been done but the corners still needed filling in. The door will seat against the firebrick door and the angle iron lintel.































The view in the door.


By the end of the weekends work (a day and a bit of effort) it looked like this.































The chimney arch was up.































































And the corners filled in.
































The inside of the corners.

Well it's been a while and quite a bit has happened.  The chimney throat has been built up a few courses and the concrete cladding poured.  I've even lit a few small fires.


Lighting the very first fire, if you look closely you can see the base of the chimney mocked up where it joins the dome above the door.  The rebar is just there to support it a bit.






























A fire always attracts a crowd, especially when it's in an oven.






























A few weekends later and the cladding is going on the oven dome, about 75mm thick all around.  The smoke is from a small fire to warm the dome sop it expands a bit.  I wish we had a heater, fires are a lot harder to control and the dome got a bit warmer than planned (I ended up cooling it down with brief squirts of the hose inside)!  Such is life!






























Close up showing the layer of aluminum foil between the bricks and concrete and the wire re-inforcing mesh.  The brick chips are holding the mesh off the foil in the middle of the concrete layer.  I was supposed to take them out as I went, but I forgot about 2 or 3 until it was to late to find them in amongst all the concrete.






























I mixed about 0.5m3 of concrete by hand, by myself, in one afternoon.  I was completely shattered when I finished @7.15pm.  The last hour and a half was done with a head lamp, and 15 mins after I finished our babysitter arrived so my wife and I could go out for dinner.  So no photos of the finished cladding.  I did uncover it a couple days later and take the forms off.  You can tell that the top was done in a rush!  I'll take photos next time I work on it, in a couple more weeks.































Technically speaking once the cement has cured I could cook in it now, but I'll try and finish the housing, chimney and insulation before I get to carried away using it and never quite get around to finishing it!

Matthew

Olly,

I've got 4 thermocouples installed.  One goes into a firebrick in the hearth that has a hole drilled to about 25mm from the cooking surface, so it's not set in the concrete but in the bricks that are laid on top of the concrete and then it just passes down through a hole drilled in the concrete.  My thermocouples had not arrived when I laid the hearth so I drilled all the holes and then poked the wire up and cemented it in place later.

The other 3 are in the dome, the first brick above the wall about a third of the way back in the oven.  From memory I can't remember exactly which arch.  I'd have to look at my notes when I get home tonight.  The first one is again drilled into the brick about 25mm from the internal surface, the second at the junction of the bricks and concrete cladding and the third on the outside surface of the concrete cladding.

It's basically the standard arrangement recommended in the Bread Builders.

I haven't used them yet, but I've got a pretty cheap handheld meter that I will plug into the termination of each wire as needed.  I'll post a photo once it's finished but that probably won't be for a wee while yet.  I still need to get a box to put the terminations in and a mount for the termination block.

I got the wires and terminations from Omega on the advice of Alan Scott and the meter from a local electronics retailer.

The hearth is ever so slightly bigger than the standard 32x36" in the bread builders.  I did measure it once, but again it's at home in my notes I think.

Matthew

*edited thermocouple position after checking photos.

I also need to mount my thermocouple terminations somewhere, then I'll be cooking with wood....

Matthew

Hi there

Nice oven!

Could you please let me know where you get a wire mesh like that for the dome? Also, is the foil normal cooking foil, and if so what thickness.

Many thanks

Martin Noakes

I'm in the U.K so; I presume it was a flat wide section of wires and you bent it to fit your design.

Martin

Well the chimney and brick frontage are now finished, I have my fire permit (though I need to add a grill on top of the chimney to catch hot embers that might try and escape) and I am now preparing to insulate the oven and put the roof on.  After that I will need to make a few ancillary bits like a door, and ash scraper and a peel that reaches all the way back.

It's getting there.

Slowly but surely getting higher.

The chimney is finished in time for Christmas!  The pizza party was booked and I'll start a new post to show those pictures.

 

Matthew