Materials list with quantities
For building new MTo oven design
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
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 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 exfoliated Vermiculite grade 3 (bigger or smaller size, although not a complete dust particles, can be used whilst the same cement to vermiculite etc. material mixing ratio remains the same.) Often I get equivalent stuff to Vermiculite for price at 30 to 40 bucks per full UTE (6′ x 8′ tray) which is a volume amount sufficient for 2.5 ovens jobs!
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