Alternative foundation

[dabstar]

Hi all,

I am starting to plan my oven in Copenhagen, Denmark. I've seen a guy in a blog doing a foundation just with concrete blocks (in Danish: Pizzaovn som Land Art). Dug down 18" and placed concrete blocks on top of each other like you would do on top of a "normal" pompeii plans foundation slab.



Is there a reason this is not more used? Denmark is cold in winter with some frost (think Massachusetts weather) so that has to be accounted for. Usually in Denmark you say 36 inches below ground for frost-proofing a foundation.

It seems rather easy to me to do like the picture but I am wondering if the normal foundation slab would be a better choice.

David

[Muscats]

dabstar;

I was thinking of doing the foundations in this way as well, however, on reading more about the reason for a slab foundation I believe it is to disperse the weight of the oven over a larger area and also to keep everything on the same plane i.e. even if the slab moves a bit the dome and oven floor move with it evenly and remain flat.

The problem with perimeter foundations is that if one area of the foundation moves it is likely to cause distortion of the oven floor causing stress on the dome and resulting in cracking.

So you would need to ensure the foundations where absolutly stable.

After building quite a few retaining walls with deep foundations I can tell you there is no way to eliminate movement complete.

Paul

[dabstar]

Thanks for your reply. I have decided to go with a traditional foundation slab. Excavation for it started this weekend. See more at http://www.fornobravo.com/forum/f8/d...ild-12774.html (Davids WFO build)

[Muscats]

Sounds like a safe move.
I notice on your build forum that you are planning to hand mix the concrete. Yes, you can use it for the slab, cores and hearth floor. You will need to get some sand in addition to the gravel/aggregate. The portland cement should have mixing ratios on the bag if it is anything like Australian packaging. It is easy to mix the concrete in a wheel barrow with a chipping hoe it just a lot of hard work.