Has anybody out there built the Tom Jaine oven? Forum Guidelines Discuss Has anybody out there built the Tom Jaine oven? in the Good Background Information forums; I have started building the oven based on the plans in the Tom Jaine book. I have doubts about the ...

[shepster]

I have started building the oven based on the plans in the Tom Jaine book.
I have doubts about the thickness of the walls. I have constructed the slab and walls and am about to backfill as per the plan. If anybody else has built one It would be good to talk!!!

[SpringJim]

What about some more details on your concerns? Too thick or too thin? What are you trying to accomplish with the Tom Jaine?

[dmun]

"Backfill" sounds ominous. Can you give us some details? What's the plan for insulation?

[Ken524]

Shepster...

Welcome to the board! With those kinds of questions and concerns I would strongly recommend that you STOP building and post some photos of what you doing.

[shepster]

Yep I have stopped building! The walls are constructed of 100mm wide concrete blocks. The wall is 4 blocks high and only single skin. He suggests (Tom Jaine;building a wood fired oven) that the void in the middle which is 1.7m x 1.7m be backfilled with sand and rubble etc. Problem is I am concerned about the pressure that would be on the walls. Once backfilled, 3 lintels are placed across and the backfill is used to cast the base
Any opinions.............?
Photo to follow

[Ken524]

Yeah, I really need pictures. I don't have Jaine's book and don't really understand what you are talking about. Are you building an oven stand right now or the actual oven?

[shepster]

Forgive me as a newbie am trying to work all this out.
Picture is in Hearth and stand area as shepsters base or PhotoPlog - Error

[jengineer]

Now we got it. The walls do not have structural support to keep them in place. I would be concerned about the sides not being ties in place. The walls at the moment are essentially free standing. Backfilling means that the void will take the place of structural support. In a sense you have built a retaining wall. The rubble once it is properly compacted should nicely form the base. Our concern now will be to make sure that it is structurally sound. This may be a economically viable method but is not one that we use as the area under the oven can be used for storage and in some cases allows access to put in more insulation if it is needed. If you fill it in and your insulation is not sufficient then there is no way to go back and correct it. Our motto here is insulate insulate insulate and use the correct materials to do so.

Has this been build on a concrete slab or has the soil been leveled?
By using cinder-blocks for a wall the Pompeii plan is solidly built. You can get a free copy of it by looking in the shopping area.

Again it would help the forum if you can spend a few hours on a word file and give some more detail about the build before you get too involved. It is easier to restart at this point than further down the road.

je

[shepster]

Thanks
The plan that I have been following says that the compacted sand etc forms part of the heat store. In fact I live in a 400 year old house and we found one of these completely encased in about a metre of sand.
The base is a 9 ich reinforced concrete slab so no probs there.
What do you use for insulation in the base? I was going to use firebricks bedded on mortar once the hearth base was cast.
I will have a look at the other plans.
Thanks for advice

[shepster]

Have tried downloading the plan but it seems access is denied. Is that anything to do with me being in the UK?
Shepster