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Post by jagnut on Mar 3, 2016 21:15:28 GMT
Hi to you all, am new to this site and am gland that I found it I wanting to build a wood oven around 1meter radius . I have been reading all the comments on insulation and what types of brick and cement mix's. My budget is a £1,000 .MY BRAIN IS COOKED and were can I bye the fire brick at a good price advice. am looking to build a dome type oven 1meter dia, and I would need some advise on height of dome and door opening as I have read that it needs to be 63% of dome height?. Read more: ukwoodfiredovenforum.proboards.com/conversation/3588#ixzz41sMH3Dr5
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Post by oblertone on Mar 3, 2016 22:03:34 GMT
Your 63% figure is correct and something to aim for, but while this is the optimum a little either way won't worry your pizza; as to door width, approximately half the width of your oven is again optimum.
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Post by downunderdave on Mar 4, 2016 3:09:35 GMT
Your 63% figure is correct and something to aim for, but while this is the optimum a little either way won't worry your pizza; as to door width, approximately half the width of your oven is again optimum. The oven door width is not really dependant on oven size. For example a really small oven will require a door width more than half the oven diameter width or the oven would become unworkable. My 21" diam oven needs more than a 10.5" wide door. Working with that would drive you nuts. Likewise a big oven, say 44" having a 22" wide door is going to cook the cook. There is plenty of air intake with even a small door, in fact some folk make what they call a "blast door" which blocks off all but the bottom couple of inches of the doorway, to get the fire really cranking, so more air intake is not the issue. The main issue is having a door wide enough to be able to reach into the oven comfortably, obviously the larger ovens require the door a little wider to be able to reach to the sides more easily. Regarding the 63%, I have formed the view that this is far less important than most would lead you to believe. I redesigned one of my ovens by raising the dome another 2", consequently bringing the door ratio to 65% and found no difference in oven firing or performance.
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Post by jagnut on Mar 4, 2016 21:11:44 GMT
Hi downunderdave thanks for the reply so what would the correct height be for the 1 meter dia oven be than or do you just build it inward . am asking these question as I have not built an oven before and I would like some feed back from experienced oven builders
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Post by downunderdave on Mar 4, 2016 22:07:59 GMT
If you are building a hemisphere then the internal height will be half of the internal diameter and the door height around 63% of the internal height. Some builders like to build a low dome, often referred to as a Neopolitan style after those ovens commonly found in Naples. The dome being lower means more intense heat to cook the top of the pizza. Their downside is that the dome is less stable, compared to a hemisphere and cooking other stuff like roasts and bread becomes problematic because of less height at the base of the dome inside the oven. A hemisphere is a good all round design.Are you planning to cast or use bricks for the dome?
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Post by jagnut on Mar 4, 2016 22:56:44 GMT
Hi downunderdave am planning to build a hemisphere using 230x114x64mm 42gd 42% alum fire brick for the hole build am at the planning stage I have drawn the circle out line on my workshop floor to see the rough size of it and to calculate the number of bricks needed for job . The cement for the bricks I do not now what to use and the vermiculite mix if this is the best.The part list is as follows floor base going to use vermiculite mix 4parts vermiculite and 1part cement then calcium silicate base then fire brick for base, then for outer thermal layer is going to be lbp Blanket 1200gr 25mm thickness chicken wire ? any thoughts on the above or am I going in the right direction. oh and what size flue do I use 6" thanks again .
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Post by downunderdave on Mar 5, 2016 2:18:24 GMT
Hi downunderdave am planning to build a hemisphere using 230x114x64mm 42gd 42% alum fire brick for the hole build am at the planning stage I have drawn the circle out line on my workshop floor to see the rough size of it and to calculate the number of bricks needed for job . The cement for the bricks I do not now what to use and the vermiculite mix if this is the best.The part list is as follows floor base going to use vermiculite mix 4parts vermiculite and 1part cement then calcium silicate base then fire brick for base, then for outer thermal layer is going to be lbp Blanket 1200gr 25mm thickness chicken wire ? any thoughts on the above or am I going in the right direction. oh and what size flue do I use 6" thanks again . Yes you are on the right track. I think 5:1 vermiculite, cement is sufficiently strong enough for under the oven. Remember that the more cement you add the less it will insulate. Mix it in the ratio of 5 parts vermiculite, 1 part cement, 3 parts water. (I find using half vermiculite and half perlite makes a better mix than either of them alone. Once it has set it is a good idea to leave it uncovered for a minimum of a week to allow the sun and wind to dry it it out partially. If you build straight over it you lock in the water and it will take longer to dry with fire. For the mortar for the bricks, most builders have found 3:1:1:1 sand, cement,lime,clay perfectly adequate and cheap. One layer of 25 mm thick blanket is not really sufficient, you can either add one or two more layers of it or if cost is a problem you can use a 10:1 vermicrete mix over the blanket. Are you planning a dog kennel enclosure style or an igloo style? A 6" flue is the correct size for a 36" internal diam. oven.
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Post by jagnut on Mar 8, 2016 21:14:16 GMT
Hi again downunderdave, the last couple of day I have been pricing up the base ect it is going to be a dog kennel type. I have a friend in the building trade so I sent him my material list and he got me a quote, bloody hell I said to the quote its the bricks which are expensive .so I used the forums account at Jewson today the sales rep looked up the account and said no problem . And it was slightly cheaper result it works ,so any way I have some more question for you if you do not mind .Can I use the hole fire brick 230x114x64 width ways to build the dome as I've seen a lot of pictures of people cutting the bricks in half does this alter the thermal efficiency of the oven or do they just do it for keeping down the cost and easier to build .
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Post by diggerjones on Mar 8, 2016 21:58:22 GMT
I would suggest using halves will be alot easier. If you imagine what it would be like near the top. I have not built mine yet so no expert.
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Post by oblertone on Mar 9, 2016 0:01:38 GMT
The gaps at the back of a full brick will be considerably bigger and will take some filling; half bricks are the way forward and cheaper too.
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Post by downunderdave on Mar 9, 2016 3:33:22 GMT
The gaps at the back of a full brick will be considerably bigger and will take some filling; half bricks are the way forward and cheaper too. I agree and in addition using full bricks does not allow you to get a good curve on the inside. The problems become greater the higher you go because the radius gets smaller for each row.
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Post by chas on Mar 9, 2016 10:51:01 GMT
The gaps at the back of a full brick will be considerably bigger and will take some filling; half bricks are the way forward and cheaper too. I agree and in addition using full bricks does not allow you to get a good curve on the inside. The problems become greater the higher you go because the radius gets smaller for each row. And you'll find smaller, mis-shapen pieces useful too - quite often the level courses turn into something of a spiral near the top and you'll be hunting through the barrow for just the right bit. A 'regular' half, it won't be, let alone a full. Chas
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Post by arnold9801 on Mar 9, 2016 19:25:05 GMT
Downunderdave
I would love to build one as well but the issue of cost is the main drawback. Therefore would you be able to let me know the cost of yours and how close to your 1k limit you got?
Perhaps others could advise on costs as well re their ovens?
Regards
Arnold9801
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Post by downunderdave on Mar 9, 2016 20:38:55 GMT
Downunderdave I would love to build one as well but the issue of cost is the main drawback. Therefore would you be able to let me know the cost of yours and how close to your 1k limit you got? Perhaps others could advise on costs as well re their ovens? Regards Arnold9801 After building an oven most are keen to have another go but do it better. There's a lot to be said for building a cob oven first. Regarding cost it could be built for zero cost. Providing you keep an oven small (mathematics of increasing volume is a big factor) you can keep both the cost and labour down enormously. I manufacture ovens but was unable to price them under A$1000, although I'm pretty close.
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Post by davenott on Mar 9, 2016 20:52:45 GMT
Downunderdave I would love to build one as well but the issue of cost is the main drawback. Therefore would you be able to let me know the cost of yours and how close to your 1k limit you got? Perhaps others could advise on costs as well re their ovens? Regards Arnold9801 My build has cost me approx £1100. The fire bricks and their delivery was the largest cost. For the outside of the oven I bought a full pallet of bricks cheaply left over from a local house build (found on 'FridayAd') and some used roof tiles from someone who had a dormer roof extension (EBay). Some other items I was given free. Good luck with your planned build. Dave.
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