Lighten Up

[bbell]

I'm sorry if this is posted twice... New to Forums.

I'm wondering what other materials have been used other than concrete blocks. I'm trying to build an oven with as little weight as I can due to it's position atop a backfilled retaining wall.

Any ideas on lighter construction for the base?

Thanks!

[Bandrasco]

Re: Lighten Up

Bbell,

This sounds like a good question for a professional, like an engineer. I'm not aware of anything lighter than cinder blocks that have the same strength.

Good luck!

[nissanneill]

Re: Lighten Up

Hi bbell
there are several of us who have built their ovens on top of retaining walls including myself.
You need to make some decisions as to the type of oven, size and thermal mass that you want (what you really want to use the oven for), before you start looking for the lightest materials in which to build your oven.
I built a 40" Pompeii over the corner of a retaining wall without problems as the back of the oven is cut into the original soil but most of it is over backfill and 2" rock which I used for drainage.
I suggest that you have a look and read through my build (just click on the link of this reply) the get ideas.
You could always post hole dig some angled piers filled with concrete and a but of reinforcing rod and then incorporate a couple of reinforced concrete beams in your hearth slab.
Build your oven with well proven products rather than unknown 'light' materials.
You also have the rather more expensive option of purchasing a modular oven, but are not anywhere near the fun nor satisfaction of building your own.

Neill

[bbell]

Re: Lighten Up

Thanks Neill

You're right and I don't want it to end up in the ravine below. I'm toying with Steel legs wrapped with cement backer board, railroad ties (heavy), landscape timbers on their side, tiatanium for the local Boeing surplus store....

I have some time since the pad isn't yet poured.

Bill

[nissanneill]

Re: Lighten Up

Hi Bill,
what a wonderful area and location for your oven, very scenic and tranquil.
It is a pity that you have already back filled your hardwood sleeper retaining wall but a very sound foundation can still be installed with the minimum of extra effort.
I would not pour your footings as you have dug them as the back fill will settle with time and moisture, putting excessive pressure on the timber and possibility of collapse.
From your pictures, it looks like you nailed (pinned) your horizontal sleepers together but without vertical supports concreted into the original soil for strength and support. These would then have been bolted to the horizontal rails (if you wanted to keep a clean uninterrupted outer appearance) or merely laid up against them for support if they were outside of your wall.

From here, I would get an 8" post hole digger and sink a minimum of 4 preferable corner holes as deep as you can get them, at least into the virgin soil. I would also flare out the bottoms of at least the deeper back of oven holes so that the bottoms will have substantially better footprint, say trim 2" all around to give a 12" bottom.
I would also put in 2 or 3 reinforcing rods to tie your already dug slab and beam footing.
You could pour the piers separately and then your slab with edge beams, but ensure adequate reinforcing to reduce heartache later, especially being on filled material
Did you wet and vibration compact the fill?
I have put together a rough picture for you to follow should you decide to make it stronger.
If you were to place your piers under each corner, you could extend your reinforcing rods up through your corner (I think you people over in the US call them) cinder blocks, locking the whole thing together.
I hope this helps.
Cheers.

Neill

[bbell]

Re: Lighten Up

Wow! That's a great post, idea and drawing. Thanks so much!

The fill was watered and compacted with a serious compactor every 8". I also used many pieces of a walkway that I jack hammered up layered in as well. there are 6 "deadmen" that are tied to the wall and run back horizontal to virgin soil and tied to a concrete pour with rebar.

Your picture was extremely helpful and I'm impressed with how you laid it into the photo.

Thanks Neill
Bill

[christo]

Re: Lighten Up

I'm impressed, too. (but Neill continues to amaze me....)

Christo