Materials list with quantities
For building new MTo oven design
FOREWORD:
Building these brick ovens is not hard to do, many people who never held a brick have built nice ovens for themselves. Special or unknown tools are not required. Basically; take it by building gradually, focus only on the one stage that you do. From the detailed photo sequence you will see ahead exactly what will be done, and how, and when.
Each stage/step on its own (e.g. the slab, inner walls, top slab, firebricks part etc.) is a little job and easy. And stage by stage the structure grows nicely. – Minds of many of us operate more on non-materialistic thoughts by principle where every thought is energy. And what I just wrote, “stage by stage the structure grows nicely”, may feel perhaps slightly tangible in the theory. So putting the same but in other words would equal to; energy flows where our focus goes.
Not much measuring goes around, only on the ground slab for the inner and outer-decorative walls, after that the oven is risen upwards and all is done on the initial block count (if stones are used for making the outer deco walls then the depth and width lines can be 2″ – 5cm further apart, on each side, because some rocks might be larger/wider than these ordinary concrete blocks or house bricks.)
The photo sequence is detailed. To reach a stage e.g. what is on the picture 1430 in 3G MTo design, it can be done in 7 days but you do not need to do it in such timing.
Work with cement blocks filled with concrete or with firebricks progresses faster, and there is waiting one and half day (or anywhere longer) for curing the ground and upper slab for the cement to cure. Make these wooden templates for creating any arch shapes easily, you will see how and get better at it once the first template gets done.
Many women are into building wood burning brick ovens. Here is one practical idea;
If you had a friend/s to give a hand, e.g. to lift concrete blocks and gradually fill them with concrete (these cinder blocks go into 4 rows, up to hip level and after just the thinner kind, lighter in weight, block sizes follow), et cetera, it is always lovely when friends participate … You can cook for them pizzas later.
Slab dimensions for start
For the 3G MTo ground slab dimensions; what concrete blocks do you use? I reckon in USA, Canada, rest of America, England, any Country on Metric system, your standard block size is the 15-5/8 x 7-5/8 x 7-5/8 inches Actual Dimensions (16″ x 8″ x 8″), these are great for the building and are basically the same lock size that I use. There are very little dimensional differences which I always mention below in the materials list. Let me know, in comments below, in case if you choose a different block size and I will work out your ground slab dimensions according your block size – it’s easy/quick to calculate that.
* Dimensions for the ground slab when 8″ x 8″ x 16″ concrete cinders are used, dry fit:
66″ x 90″ (inches)
(There is 1 inch extra on each side in the slab – already included in the measurements.)
* Dimensions for the ground slab when 190 mm x 190 mm x 390 mm concrete blocks are used, dry fit:
1665 mm x 2245 mm (millimeters)
(There is 2.5 centimeters extra on each side in the slab – included already in the measurements.)
As you can see, the footprint of the structure is quite small. Almost like the double bed mattress size, not as big concrete slab.
The actual ground slab flat surface is 4″ – 100 mm thick and in addition the slab has also at least 1 foot – 30 cm deep and 1 foot – 30 cm wide footings all around (sized for the weight), this concrete footing/foundation is reinforced with 1 rebar in each side. The whole slab surface is also reinforced with the metal mesh cut to size.
* FREEZING CLIMATE:
In freezing climates make the footing below the frost level; it’ll need a good foundation slab to prevent frost heaving of your slab and oven. As per the usual building practice applied/common in the specific area. How deep is your frost line? If it’s less then 1 foot below or if there is hard clay, or rock ground, on which the slab will sit then you will not need more to do. But you need to be sure completely that it is the correct hard ground which does not move due to freezing, because, even-though the oven sits on small surface, but it is heavy. If the frost line points deeper, where the ground gets soft in spring and can move, you will need to dig down and then build up some quick walls. The fastest approach I have seen, was digging down below the frost line and filling it with tapped down or vibrated rock all the way up just near the ground level and then twice as thick slab was poured directly on the rock. It seems to work fine. Still, I would rather create a nice footing at the bottom and from it rise cement block walls. That is the common and more correct approach to me.
Further to boost efficiency
If you would like to have more space for the thermal insulation thickness around the oven, the gap between the oven part and the surrounding boxing walls, for the structure is not accurately compact, just add one half block length into the total width. 1/2 concrete block in the front wall width, and the same, 1/2 concrete block in the rear wall. This addition will give you more room internally (for work as well if you do not prefer perfectly compact structures.) You would only add 8″ – 20 cm to the total width. However, this is just an addition, adding the half block to increase width isn’t necessary. The oven, as is, is proportionally perfectly calculated.
** See the pdf files (attached further below) for numbers of firebricks and precisely how they all go, your size 2.5″ (inches) = 64mm thickness, also 9″ long firebricks and 4.5 inches wide.
I use 3″ – 75 mm firebrick thickness as they are standard-size/cheaper to buy in Australia. Thinner bricks however are always better; even though an arch takes larger number of bricks the thinner they get, the arch gets smoother radius (nicer cosmetically speaking), PLUS, the “V” gaps in between all bricks in the arch end up smaller. Meaning; less mortar in such arch which brings more positive value for the arch than just looks.
For specific matters regarding building 3G MTo oven designs, and as you progress with building, if needed simply ask all questions via comments on these MTo pages home (or email me your questions I will reply with what you need)
Building MTo designs is faster to do and also better. The final decoration over the blocks can be just about anything, tile mosaic, stucco, render, etc. And the outer walls could also be done out of house bricks. It’s extremely easy and quick to make various kind of changes. Even scaling from the original size.
In US the house bricks size is 3″ x 4″ x 8″, which is also what oven builders use. I work with very similar house brick size, 3″ x 4-1/4″ x 9″ (Metric 75 mm x 110 mm x 230 mm) and I used 142 of them for this oven job (visible up to the point on the chimney level ending with the decorative outset reddish-brick color row plus one more row above this before last raw – see this stage precisely on the photographs e.g. 3rd-mto_2457 or the 3rd-mto_2479). Get 20 bricks more than I used to accommodate the slight difference in the size sometimes.
List of materials
HOUSE BRICKS:
Full size: 162 house bricks (natural clay bricks look nicer but also cement imitations are often used)
8 x clay pavers for the decorative 30 cm x 30 cm = 1 ft x 1 ft pot-resting surface located just outside / in front of the oven (4 of them have one round/bull-nose edge).
CONCRETE BLOCKS:
Concrete blocks 8 in. x 8 in. x 16 in. type (7-5/8 x 7-5/8 x 15-5/8 inches Actual Dimensions)
Or Metric 190 mm x 190 mm x 390 mm (e.g. Au. large standard size block.)
Full length size: 93 blocks
Half length size: 26 halves
The thinner concrete blocks 4 in. x 8 in. x 16 in. type (3-5/8 x 7-5/8 x 15-5/8 inches Actual Dimensions)
Or Metric 90 mm x 190 mm x 390 mm (e.g. Au. 90mm thinner standard size block.)
Full length size: 79 blocks
Half length size: 13 halves (four out of these thirteen get cut in ~half furthermore to make 8 quarters)
* CAPPING TILES
Size: 8 x 16 x 1 to 2 inches thick (size to suit/cover the 8″x8″x16″ concrete blocks)
Or size: 190 mm x 390 mm x 30 mm thick (size to suit/cover the 190 mm x 190 mm 390 mm concrete blocks)
The 4″ – 10 cm thick thermal insulating layer is poured on top of these cap tiles. Other similar material could be used instead, including pavers, various tiles, etc.):
22 capping tiles
FIREBRICKS (exact numbers):
For the 2-1/2 in. x 4-1/2 in. x 9 in. firebrick size –
248 x firebricks
Plus 17 firebrick splits which are 2 inches thick – these are for the entrance small arches.
Diagrams for MTo oven designs
Diagrams for the MTo oven’s firebrick cooking part.
Standard firebrick sizes 2.5 inch = 64 mm sections.
The firebrick arch walls floor profile.
Structural diagrams you will need.
CONCRETE BLEND / AGGREGATE (it is the mix of stones with sand – for the whole oven job):
2 cubic meters = 2.62 cubic yards
Concrete amounts converter:
concrete units converter
SAND FOR LAYING BRICKS:
0.5 cubic meter = 0.65 cubic yard
PORTLAND CEMENT (mixing concrete in ratio 4:1 – ALWAYS in volume sense – plus includes amount for mortar to work with house bricks):
0.7 cubic meter = 0.92 cubic yards = 24.72 cubic feet
0.7 cubic meters of cement = 1,054.01 kilograms = 2,323.71 pounds
Cement amounts converter:
cement units converter
LIME – Hydrated Lime Standard Grade, this is the same lime as builders use for making mortar – calcium hydroxide Ca(OH)2
5 x bags (20 kg each bag) 20 kg = 44.1 pounds
HEAT RESISTANT MORTAR:
(* for work with 2.5 inch thick firebricks a commercial premix ‘air-set’ refractory mortar in bucket can be used as the ‘V’ gaps between firebricks in arches are small. One bucket is plenty, not much of this mortar is used.)
1 x 15 Liters bucket of premix refractory mortar = 3.96 gallons (~4gal)
1 x small bag of fireclay (for the thin firebrick-leveling layer which goes under firebricks in floor)
REINFORCING METALS (Reo):
Reinforcing Mesh – Sheet (same as used into concrete for making driveways): 1
(Square Rib Mesh Standard Sheet – 6 m (length) x 2.4 m (width) = 14.4 m2)
Reinforcing Bar: 2 x 64″ long pieces, 2 x 88″ long pieces, 1 x 55″ long piece (16 mm = 0.66″ in diameter, or stronger)
THE CLADDING explained:
concrete cladding information
THE MORTARS explained:
refractory mortars information
THERMAL INSULATION – Vermiculite or Perlite (or fly ash):
How to properly mix Vermiculite by hand is explained – read the whole page: thermal insulation types information.
9 x 100 liters bags = 32 cubic feet
(Do not save on volume of thermal insulation – for efficiency it’s logical to add even more, on top especially.)
Various heat resistant insulation types are available for use, not just the not so cheap exfoliated Vermiculite grade #3 (bigger or smaller Vermiculite size, although not a complete dust particles, can be used whilst the cement to vermiculite mixing ratio remains the same.) Often I get equivalent stuff to Vermiculite, BUT, for much lower price, at 30 to 40 bucks per full heaped UTE (6′ x 8′ tray as much as it loads) which is a volume/amount sufficient for 2.5 to 3 ovens jobs!
The above information on savings is being shared with every person who gets our Rado Hand oven building plans … for the assistance. For example, specifically just this insulation material on its own saves us 450 dollars per one oven job. How’s that? Enjoy!
Respond to the Materials list with quantities article:
9 Comments
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Hi Rado, I just found a guy who has pallets of unused fire bricks that he’s selling for $1 (US) per brick. I bought 300 of them in prep for building a 3G MTO. The problem is the bricks measure 9×4.5×3 inches. How do I compensate for the 3 inch thickness??
By Arlen Fletcher
Good afternoon Arlen,
It is a very good price per firebrick! I would straightaway take all of them he has.
I’ve used the same 9×4.5×3 inches firebrick dimensions, it is the standard size over here (in millimeters we measure them 230mm long x 115mm wide x 75mm thick). In US and Europe you guys have the 2-1/2 inches thickness (or 64mm) instead of 3. But it doesn’t matter at all, you will use fewer of them for the same oven internal space. Have a look at the 3″ thick firebrick count for the hearth surface, for walls and for vault arches how they go and how many fit in each place.
By Rado
Arlen, Does he have anymore of those firebricks and where is he! LOL.
This is looking to be the choke point for me personally getting a better price on and collecting around all material from advertisements. The work itself on the oven will be basic per say.
By Vince Nylin
Hi Rado,
I have about 600 standard clay bricks that people use in NZ for cladding the house. The dimensions are approximately
l=230
h=70
w=75
with 5 holes in the middle. Can I used them for the dome and the cooking surface?
My plan is to fill the holes with some clay/sand mix (1:3 ratio maybe) to increase the mass and retain more heat. And maybe use 2 layers of bricks on flat (140mm height) for the cooking surface.
Would be good if I could reuse those bricks as I got them pretty cheap.
Also you mentioned in the reply to my email that I will have to reinforce the slab I was planing on building the oven on. The slab is 100m thick with a reinforcing mesh in the middle. It sits on 10cm compacted brown rock on compacted dirt.
How can I reinforce it? Thanks for any suggestions
Thanks!
By Nono
Good day Nono,
The measurements would be all right but it would be totally better if you could locate somewhere a true ‘solid clay bricks’ instead, for the firebrick part. Most probably these wouldn’t last exposed to the heat. But certainly they would be perfect for the outer non-refractory part of this oven structure.
The slab would be reinforced well, as you mentioned. The only thing is that the area around the oven, just under the oven walls, would miss the reinforced 30cm or 1 foot footing. Because the oven is heavy. If the existing slab is the only option in your case, and if it sits on a well compacted hard ground it could work, but would be still much better if you created another reinforced slab on top precisely-only for the oven footprint-surface area. Then the pressure of the oven walls will be distributed/spread across/over a large area the whole secondary slab.
By radko
Hi Rado – I will be using #1 and #2 arch bricks for the vault of the oven. At what angle are you cutting the skew bricks that form the base of the arch? Did I miss that somewhere in the drawings?? Thanks!
Bo
By Bob Kayser
Good day Bob,
Thank you for asking. What are the exact measurements of your #1 and #2 arched firebricks?
Anyway here goes below for you Mate, it’s very easy and quick to create the skew firebricks for each side:
1. First place the wooden arch template in place between both side walls and set it into position – image #0985
2. Then temporarily place one firebrick in the first spot of the arch and hold it in there, it will perfectly show you the accurate angle of the arch firebrick to the horizontal arch firebrick.
3. Put a piece of a cardboard onto these the two bricks and mark the accurate angle lines. Cut it out with scissors and you have an impression template of triangular shape.
4. By using your template mark the lines onto a firebrick with sharp pencil (a pen works too) to make the skew firebricks.
See images #1181, #1182 and #1183 (showing on the next page for oven firebrick entrance details.)
5. Do the same on the other side (or at least double check the other side angle even-though it should be the same in mirror image.)
* I cut these using a quality diamond masonry cutting wheel on a small hand-held angle grinder, one cut per side. Keep the off cut triangular pieces for finishing the oven entrance.
By radko
Hi Rado,
Trying to find a good balance between a pizza oven and an oven suitable for baking and slow roasting.
In Norway we typical build our traditional ovens from 4.5″ (110mm) fire bricks covered with a 5″ (130-150mm) layer of sand used as heat absorbing mass. And insulation thereafter.
I planning to use not only one layer but two layers of fire bricks that will give me a total dome wall thickness of 9″ (220mm). And isolation thereafter. I will not use any sand our cladding for heat absorbing.
The floor will consist of two layers as well. Bottom layer 4.5″ (110mm) fire bricks and on top 1.3″ (33mm) layer of Saputo Biscotto Pizza Stones .
My concerns will be that it will take too long time to heat up this oven?
Thank you for answer.
By Roger Akse
Hi Rado,
I have a lot of fire bricks. Would it make sense to put second layer of them on top of the first layer in order to avoid the cladding?
Thanks.
Tomo, Texas USA
By Tomo Curanovic