New Design

[herrbeckley]

I tried to ask this question in my previous thread (beginner with a foundation problem) but got no response. Thought it might be seen on this new thread.

After a hiatus of eight weeks or so, I'm back at it. How does this sound to you folks. Two concrete filled brick walls spanned by cedar 4 x 4's to form a base. Then a layer of insulation, then normal brick, then hearth floor. Beams span only about 28" and the will be secured flush to one another. I think that the wood will be protected from the heat of the oven and cedar is a tough wood perfect for exposure to the weather. I'm about to get started on this (brick walls are complete), so if this is really stupid please let me know.

My original plan to use the arch for support was beyond my skill level (three collapses).

Very Respectfully,
Tom

[Les]

Tom,

I think I need a sketch - it's hard for me to envision exactly what you are trying to achieve. In regard to cedar, it's an evergreen - soft wood. And ALL wood will rot in time. More so when exposed to heat and concrete. Just my opinion, maybe others will chime in.

Les...

[brokencookie]

Originally Posted by herrbeckley

Two concrete filled brick walls spanned by cedar 4 x 4's to form a base.

I am confused as to why you want to use wood here at all. Concrete with rebar will end up being cheaper and much more duable. If you want the appearence of the cedar, put it on as a veneer afterwards.

Originally Posted by herrbeckley

Then a layer of insulation, then normal brick, then hearth floor.

This appears to be in the wrong order. It should be hearth floor, insultation, then whatever else. Remember, the insultation prevents heat from bleeding out. In your listed configuration, you would be heating the hearth floor and then heating the bricks ( are you making a retained heat oven ?). Ideally you should heat the hearth floor and keep that heat from reaching anything else by using the insulation.

Hope this helps
Bruce

[dmun]

Anything structural in wood below the oven is a really bad idea. All you need is something junky to hold up your slab temporarily while it's being poured (I used scrap wood from skids.)

I don't quite understand about your fallen arch: some builders have built beautiful brick arches above their wood storage area but my theory is keep your hard work and finish materials for where you can see them. Really, just a plain old reinforced concrete slab is all you need. If you want a decorative arch, just incorporate it into whatever your outside finish material will be.

And yes, your insulation layer goes directly below the brick cooking floor. Four inches of vermiculite concrete, or two of refractory insulation board is suggested.

[herrbeckley]

But it is done in German Bake ovens. I don't know if they use cedar, but a wooden deck made out of beams laid flush together, supported by two masonry piers, is a common method. The wood beams can support the weight as well as a slab. It's free (for me) if I use cedar, and cedar seems to be very weather resistant.

[karl]

If you dimension the beams correctly (not only for strenght, but also for maximum bowe down) and insulate properly there should not be a problem. Cedar is an oily type of wood and, as you say, should stand the weather quite well (is used in boats). And it will be shielded from above anyway? Remember to put in a water resistent thin layer between the (whatever) layer that against the wood to avoid any moisture in that layer to wet the wood during prolonged periods. You should be very careful in doing the same between the wood and the concrete were the beams are anchored. It is very important for the wood to stay dry (dry up) for prolonged periods to prohibit rot. But, as is stated by others, you cannot assume that the wood will stay up as long as reinforced concrete (assuming you will use sufficiently robust reinforcement bars, - corrosion!).



regards from karl

[Antonio D.]

Hi Tom,
I have run into the same problem. When we had our pool dug 3 years ago I had a base dug and filled it in with concrete. When I was ready to start my oven I realized my base was to small. I supported 5 inches of reinforced concrete with 3 1/2" x 3 1/2" x 3/8" angle iron. my base was 45" x 53". My hearth is 72" x 63". I made a 10" deep form and poured 5" concrete ( 10" around the outside and embedded 5" vermiculite concrete in the center.
check out my pictures.

Tony

http://www.fornobravo.com/forum/photoplog/images/4407/medium/1_IMG_0184.JPG[/IMG]

http://www.fornobravo.com/forum/photoplog/images/4407/medium/1_IMG_0196.JPG[/IMG]

[Antonio D.]

Hi Tom,
I have run into the same problem. When we had our pool dug 3 years ago I had a base dug and filled it in with concrete. When I was ready to start my oven I realized my base was to small. I supported 5 inches of reinforced concrete with 3 1/2" x 3 1/2" x 3/8" angle iron. my base was 45" x 53". My hearth is 72" x 63". I made a 10" deep form and poured 5" concrete ( 10" around the outside and embedded 5" vermiculite concrete in the center.
check out my pictures.

Tony

http://www.fornobravo.com/forum/photoplog/index.php?n=1439[/url]
http://www.fornobravo.com/forum/photoplog/index.php?n=1440[/url]

[dmun]

Hi, Tony,

I think you're trying too hard on embedding your images. You can either paste the [img]...[/img] data into your post, or hit the postcard icon above the text box and paste the URL of the image there.

[Antonio D.]

Thanks
I'll try again

http://www.fornobravo.com/forum/phot...1_IMG_0344.JPG