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Post by downunderdave on Mar 7, 2016 9:06:13 GMT
Was thinking about laying a sheet of Kingspan insulation over lintels first. I don't know that product or its density or strength. It should be ok, just use your own judgement. |
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Post by chas on Mar 7, 2016 10:06:52 GMT
Was thinking about laying a sheet of Kingspan insulation over lintels first. If that's the stuff that's like Cellotex, it does seem to be quite difficult to set fire to... If there's room (ie depth available) what about: lintels - Kingspan - slabs - insulating cast - floor? They could be cheap thin slabs, but they would a) add to insulated floor mass, b) spread the load of the oven construction above. All those foam sheet building products hate any point load... Chas |
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Post by zelige on Mar 7, 2016 18:34:00 GMT
Just a thought ... I'd check what temperature the Kingspan might be subjected to and also what's its weight-bearing capacity - ovens are very heavy hot objects.
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Post by diggerjones on Mar 7, 2016 18:43:15 GMT
As I see it, it will be lintels,plastic sheet maybe a sheet of 25mm/50mm Kingspan,insulated 4"slab then fire bricks floor. You put Kingspan under concrete house floors so will be plenty strong enough. I only thought of Kingspan because I have just picked up 2 sheets 1 x 1" and 1x 2" free off my village website. I have started to think of the insulation slab now, could some have a look at my link and tell me if any of these recycled materials be any good. This is the place where I will be getting my bricks from. grange-aggregates.co.uk/aggregate_materials |
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Post by diggerjones on Mar 10, 2016 21:50:07 GMT
Been to pick up a 1/2 pallet of a mish mash of unused fire bricks and a bulk bag of timber off cuts. Made a £20 donation to charity. Not sure how I will use them. One thing I probably will do, is put 4" under my floor. And maybe use them higher up the dome because they are only about 2" thick  . |
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Post by diggerjones on Mar 13, 2016 19:52:44 GMT
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Post by diggerjones on Mar 17, 2016 23:29:42 GMT
Fetched my reclaimed bricks from Stoke on Monday  |
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Post by diggerjones on Mar 20, 2016 20:44:44 GMT
 I changed the hearth. When I picked the bricks up the chap had some big pieces ideal for the floor. |
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Post by diggerjones on Mar 20, 2016 20:49:30 GMT
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Post by diggerjones on Mar 20, 2016 20:55:22 GMT
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Post by cobblerdave on Mar 20, 2016 23:08:06 GMT
G'day
I realize that the entrance is a mock up at this point. I'll just mention that it's a good idea to leave a revel, a lip to provide a seal for an oven door in the future.
Regards dave
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Post by diggerjones on Mar 21, 2016 20:55:58 GMT
Yes dave I have done plenty of research. I will be putting a lip. My only concern at the moment is the fire/heat break. How important is it. Instead of butting the bricks up to the arch. I have built it like normal brickwork but with no fire cement bonding them.
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Post by cobblerdave on Mar 22, 2016 10:21:47 GMT
G'day
I personally don't think it's important. I don't have a heat break and don't notice a great drop in temps any much differently to other ovens. I find that the radiated heat from the fire warms the entrance anyway rather than being a big cold heat sink. I think a heat break could be more important in a commercial oven flashed and hot for extended periods.
Building the entrance way as a separate structure is a good idea as you will
Get natural cracking in the mortar anyway as the two expand and contract differently.
There is no right or wrong to heat breaks
Regards dave
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Post by downunderdave on Mar 22, 2016 12:03:02 GMT
G'day I personally don't think it's important. I don't have a heat break and don't notice a great drop in temps any much differently to other ovens. I find that the radiated heat from the fire warms the entrance anyway rather than being a big cold heat sink. I think a heat break could be more important in a commercial oven flashed and hot for extended periods. Building the entrance way as a separate structure is a good idea as you will Get natural cracking in the mortar anyway as the two expand and contract differently. There is no right or wrong to heat breaks Regards dave If you have a heat break apart from reducing heat flow via conduction, if made from a flexible material like blanket or lean vermicrete it can also act as an expansion joint, allowing the inner parts of the oven to expand without putting stress on the cooler parts of the outer arch and shell which haven't expanded. I've seen plenty of outer decorative arches that have cracked and believe that the lack of such an expansion joint is the cause. There are two types of blanket. One is a class 2 carcinogen (tumours in lab rats but none in humans) the other is carcinogen free. In any case you shouldn't have any exposed blanket in the oven. Another alternative is just to allow it to fill with ash. |
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Post by diggerjones on Mar 23, 2016 20:47:04 GMT
Thanks, got my arch cemented in. I used thin fire bricks, wonder why when folks are ordering bricks they don't order thinner bricks for the arch.  |
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