Short Landing?

[JoeT62]

My post on this got buried somewhere - can't find it myself now. Anyhow, if I put a 42" oven on center I have very little vent/oven landing area. I can push the center back a bit to gain a few inches for the vent, but was wondering if anyone had any experience with this?

I have also thought of extending the front like Balty did, and of course also the possibility of decreasing the size of the oven.

The pictures show a dry run of a 42" diameter on center.

[CanuckJim]

JT,

If you push the oven back a bit, you'll have precious little room for insulation. Suggest you extend the front beyond the block work instead.

Jim

[jahysea]

JT,

I have a 42" oven and I can't imagine it being smaller.

And I'd have to agree with the wise Canadian. You can't go backward much more, but you need a bit more landing to accomodate your chimney vent if nothing else. Cantilevering out would have been easier when you did the original pour, but you can still do it. Just rebar into the existing slab and pour the landing itself at floor height.

The polished concrete done by Balty is gorgeous, I'd imitate it:

[dmun]

Insulation is important. Leave room for it. Remember that your dome is a hemisphere, and you will have more room by the time you get up to vent level. I supported the back of my vent on the dome of the oven, which involved crazy brick cutting. You're better off going forward if you have the room.

[james]

I have always liked the cantilevered landing design. It gives you a nice landing, without making the overall stand larger.

Plus, the comments on not under-doing the insulation in the back are good. At the core you need to make sure your oven holds heat. If you are tight, use 100% ceramic fiber insualation (Insulfrax or like) in the back. 3"-4" of insulafrax will efficiently insulate your oven dome, without using as much space as vermiculite.

James

[JoeT62]

I have settled on making the oven slightly smaller (about 41.5") and will go with the extended apron. Actually, the insulation space in the back isn't a problem - it's the sides that get tight when the oven gets pushed back (on the corner install).

Incidentally, I think I might have found a typo on the plans related to this - the diagrams on the corner installations are labelled as 31", 35", 39", and 43" internal oven diameters -- but the external diameters in the diagrams are only 35.5", 40", 43.5", and 48". Most firebrick seems to have about a 4" width so that a standing soldier course will give external diameters of 39", 43", 47", and 51"

[JoeT62]

Oh - and I already planned on using several layers of the Insulfrax. I just hope I'll see the day!

[Hendo]

Joe,

Balty recently raised the issue of a lack of space for insulation and David had some wise words which may be applicable to your situation:

Originally Posted by dmun

… heat rises. A little extra insulation on top is more effective than on the side. Think about your house with the three-and-a-half insulation in the walls and the six inches in the attic. Same principle.

While my oven didn't get any bigger, I allowed only 4” between the base of the dome and the brick veneer walls which will surround it. Then I read that I should have allowed an extra 1” for thermal blanket as well as the 4” for loose vermiculite. However, there will be only three small areas where the insulation will be a bit thin, and right at the base, so I really don't think it will seriously affect the oven's performance. But as James has suggested, it may be prudent to stuff some additional blanket in these areas and reduce the vermiculite thickness.

Paul.

[nissanneill]

Joe,
another alternative is to elongate the oven width wise and reduce the depth a little which will enable you to push it back a little as the attached illustration shows. With a little creative brickwork, you could also push the rear back a little to make a slight teardrop shape which shouldn't affect the strength nor performance of your oven.
I tend to light my 40" Pompeii up with a fire across the hearth and then push the fire/coals back when ready to cook leaving more room than is required for multiple pizzas and bread than required.
Neill