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Firstly, can I say how brilliant this forum has been in getting me from a quiet dream to a real oven. Thank you for all the amazingly useful stuff. However, despite scouring these pages for some time I need some clarity and confidence before the final leap to the dome having built a base I am quite pleased with (picture).
I am, and have been building from recycled materials. My dome will be from quartered storage heater blocks and the hearth built from the same blocks but not cut.
I need clarity, advice, opinion, confidence building please, on:
1. adhesive for hearth to vermicrete base: there seems to be some variance between fireclay only and mixes of fireclay lime opc etc. Is there a consensus pls?
2. First dome course/chain: seems to be a strong but minority view that no adhesive should be used. Does it depend on whether the first course sits on the hearth, or sits outside it?
3. I'm a bit restricted on diameter, how short can the transition tunnel be? Is there a point at which it has no value e.g. <6 inches
My last point is one for discussion pls:
4. I have built my structural support using a potentially contentious design and I would like to invite informed and considered opinion on my design. I am fully cognisent of the risk issues and I am happy with the judgements I have made but I would welcome opinion and experience from other builders. I have a circular masonry tower with six piers on the circumference and two diametric cross walls. On this I have built and bedded a wooden hexagonal frame of 75X75 timber. My original intention was to place cut paving slabs on this frame as a base for my vermicrete slab. As I started to cut my first reclaimed 900 x 600 slab with the ensuing dust, noise and prospect of many more cuts and the risk to my lungs and the costs of diamond blades, I realised that there was no obvious reason why a timber planked base should not be used. I had lots of good, solid 25 mm sawn planking via freecycle. I considered the possibility of ignition of same via conducted heat through 75mm of firebrick, 125 of light mix vermicrete. I found a wonderful thread on here which gave some vermicrete. v ceramic blanket heat transfer data and decided that the likely temperatures at the surface of the planking, combined with limited oxygen, were unlikely to create ignition risk. Even if they did, the main risk from an outside oven some distance from the house was just an unfortunate loss of a lot of work. To reduce the risk further, I screeded the planking with a 10mm render coat to really reduce the oxygen availabilty. I feel quite content with this arrangement and I know it does not offend any code issues where I am in the uk. I am interested though to know if anyone else has used structural timber, as opposed to the usual masonry and concrete techniques?
Any way, there it is, I really appreciate all the input I have had from the forum, it's fascinating. Thanks
Jim Noonan
UK
I am, and have been building from recycled materials. My dome will be from quartered storage heater blocks and the hearth built from the same blocks but not cut.
I need clarity, advice, opinion, confidence building please, on:
1. adhesive for hearth to vermicrete base: there seems to be some variance between fireclay only and mixes of fireclay lime opc etc. Is there a consensus pls?
2. First dome course/chain: seems to be a strong but minority view that no adhesive should be used. Does it depend on whether the first course sits on the hearth, or sits outside it?
3. I'm a bit restricted on diameter, how short can the transition tunnel be? Is there a point at which it has no value e.g. <6 inches
My last point is one for discussion pls:
4. I have built my structural support using a potentially contentious design and I would like to invite informed and considered opinion on my design. I am fully cognisent of the risk issues and I am happy with the judgements I have made but I would welcome opinion and experience from other builders. I have a circular masonry tower with six piers on the circumference and two diametric cross walls. On this I have built and bedded a wooden hexagonal frame of 75X75 timber. My original intention was to place cut paving slabs on this frame as a base for my vermicrete slab. As I started to cut my first reclaimed 900 x 600 slab with the ensuing dust, noise and prospect of many more cuts and the risk to my lungs and the costs of diamond blades, I realised that there was no obvious reason why a timber planked base should not be used. I had lots of good, solid 25 mm sawn planking via freecycle. I considered the possibility of ignition of same via conducted heat through 75mm of firebrick, 125 of light mix vermicrete. I found a wonderful thread on here which gave some vermicrete. v ceramic blanket heat transfer data and decided that the likely temperatures at the surface of the planking, combined with limited oxygen, were unlikely to create ignition risk. Even if they did, the main risk from an outside oven some distance from the house was just an unfortunate loss of a lot of work. To reduce the risk further, I screeded the planking with a 10mm render coat to really reduce the oxygen availabilty. I feel quite content with this arrangement and I know it does not offend any code issues where I am in the uk. I am interested though to know if anyone else has used structural timber, as opposed to the usual masonry and concrete techniques?
Any way, there it is, I really appreciate all the input I have had from the forum, it's fascinating. Thanks
Jim Noonan
UK