Adding a chimney to a barrel build

[petemcc]

I've searched loads and while building a barrel type oven seems relatively straightforward, I can't see any way of adding a chimney without compromising the structural integrity of the arch design. The kind of thing I've looked into building is a straight clean design like this:




does anyone have any tips regarding leaving a gap in the arch without risking collapse? do I need a metal box for support? or is there a way of doing it which means the bricks will stay put? I've not built anything like this before so it's all new, any advice appreciated.

[petemcc]

Never mind, I eventually found a site which sells kits and talks you through the process, not buying a kit but I can adapt what they tell people to my own ends If anyone wants to know it's something like this:



This allows the bricks to still support the arch structure while letting the smoke out.

[downunderdave]

May 2, 2017 18:06:50 GMT petemcc said:

I've searched loads and while building a barrel type oven seems relatively straightforward, I can't see any way of adding a chimney without compromising the structural integrity of the arch design. The kind of thing I've looked into building is a straight clean design like this:




does anyone have any tips regarding leaving a gap in the arch without risking collapse? do I need a metal box for support? or is there a way of doing it which means the bricks will stay put? I've not built anything like this before so it's all new, any advice appreciated.

Before you rush off and build something like this you need to do some research. There are a number of reasons this design is poor.
1. It appears there is no under floor insulation.
2. There is no insulation over the arch causing the oven to lose heat quickly.
3. The double layer of brick will give the oven more strength but will take way longer to heat up sufficiently and causing greater fuel consumption. The uninsulated outer layer will be sucking heat from the inner layer.
4. The updraft flue design will create a much higher heat loss out the flue. A cross draft design with the oven door around 63% of the internal oven height is far superior.
5. No steel bracing or buttress ing of the walls is evident.

many beginning builders believe that a barrel oven would be easier to build than a dome and therefore go down that route without realising that a barrel oven is inherently unstable when being continually fired and the resulting expansion and contraction is considered. I suggest you look at 
community.fornobravo.com
because they have many more barrel oven builds on their site than this one. You can then see the problems I raised and probably decide a dome is a better option. If ease of building is your primary concern then consider a cob oven.

[petemcc]

Thanks for the input, I'll have a look, but I was posting the pic as an example of the style of oven I'd like to build, mine will have better insulation than that one and a reduced door opening, it was the structural weakness around the chimney outlet that I was questioning.