Do I need a support column in the center?

[Phxdt]

Below is a schematic of my build. How do I analyze if I need a center column or not? If so, how many deep?

Thx

my current progress:

http://www.fornobravo.com/forum/f8/first-timers-az-build-17591.html

[nissanneill]

Re: Do I need a support column in the center?

Assuming that your plan is your support base, I would use a temporary support down the centre of the hearth, place a double layer of weldmesh and pour your 4" of concrete. Once the concrete has cured, (max strength is achieved after 21 days) you can remove the support as it will not be supporting any serious weight. The bulk of the dome weight will be carried by the perimeter base blocks.

Cheers.

Neill

[Neil2]

Re: Do I need a support column in the center?

Reinforce your slab. You won't need a central support except , as Neill says, during construction.

I would use ordinary re-bar, 1/2 inch or 3/8 inch. A grid with 8 inch centers for the 1/2 inch or 6 inch centers for the 3/8 inch (re-bar is cheap). Hook or bend the ends.

[Cheesesteak]

Re: Do I need a support column in the center?

No - as others have said - you don't need a center column. My first oven - I built the horseshoe stand - as most here have built. I found that a 5' deep opening under my oven wasn't very user friendly. So - on my second oven - I decided to build the stand in more of an "H" configuration, with accessible storage from the front and back of the oven.

See here:



This configuration works really well for me. I can stack two rows of wood in the front storage and I've got my Weber kettle grill, charcoal, kindling, and a container of Fat Wood tucked in the back storage - completely out of sight.

Just something to think about.

[Phxdt]

Re: Do I need a support column in the center?

brilliant. I guess I will have to do that on my second, too. I have the U shaped for now.

[seattlecaveman]

Re: Do I need a support column in the center?

Man, I wish I would have seen this before starting my build... It is nearly impossible for me to crawl into the opening for my oven. I can imagine that will be where old wood goes to die since I'm not likely to get all the way back in there when the oven is complete.

[tonybaker]

Re: Do I need a support column in the center?

I used the H layout, it gives peace of mind and allows for a thinner slab. Don't bother mortaring the blocks, just stack them up, and don't bother putting rebar or concrete in them. With that heavy slab on top, they ain't going nowhere!

[calipizzanapoletana]

Re: Do I need a support column in the center?

I used the H layout, it gives peace of mind and allows for a thinner slab. Don't bother mortaring the blocks, just stack them up, and don't bother putting rebar or concrete in them. With that heavy slab on top, they ain't going nowhere!

While I agree that the weight of the slab will keep the blocks in place, it will not be as structurally sound as if you filled the cores and placed rebar in a grid, tied in with rebar in the filled block cores. Your suggestion might be ok in some places, but it needs to be taken with a grain of salt. If you live in an area with techtonic activity (earthquakes), then it is essential that the slab and foundation be reinforced.

If your going to go through the hard work of building the oven, do it the correct and safe way.

[SableSprings]

Re: Do I need a support column in the center?

I really wanted to avoid having any wood storage right underneath the oven opening, so I designed my base for two movable carts. These give me wood and party supply storage as well as the ability to hide them when needed (and extra counter space!) Note that my span didn't need any extra support. In fact my ash bin is now hanging under the ash slot in the five foot span of the front...sorry, but the bin didn't get in the last picture.

I dry stacked my block and put rebar in every other hole bent into the future slab pour level. I then stuffed empty concrete bags in the alternate holes (to save some money) and poured the slab so half the holes (top slab to foundation) had concrete and rebar in them. The result is concrete and rebar solidifying the entire structure-slab to stacks to floor. I agree with calipizzanapoletana above that it's well worth bringing the slab and the foundation together as a unit for any "earth movement".

[Neil2]

Re: Do I need a support column in the center?

Put rebar and concrete in the walls, at a minimum at the corners and ends. Bend into the suspended slab.

Rebar and concrete are cheap.

[Mike D]

Re: Do I need a support column in the center?

-Don't forget to tie all the rebar together, and yes like Neil2 says use lots of rebar. I way over built my stand and I would do it again just for the piece of mind. Your going to spend a lot of time and money on what goes on top of your stand, do it right (once).

-If I was to build another stand I would do some sort of S or H pattern to give 2 smaller storage areas. It all depends on your access around the oven.

-Good Luck
Mike D

[Phxdt]

Re: Do I need a support column in the center?

Yup, too late for me now (at least I think so- the stand is built and cores filled). I would likely to an "S".