stand question

[barbarian]

I need advise from the experienced masons out there..
OK few Qs and advise on my pre-plan
I want the base to be lower than the 41.6" from the pompei plans
also I'd like it to be easier to disassemble

so I "decided" to stack 3 rows of cinder blocks (24"), 4x8x16 blocks instead of the concrete pour (4") topped with duroc (1/2") and a final vermiculite cement pour of 5" for a total height or 33 1/2" here's the question
are there any structural issues using 5" of vermiculite since it's so spongy ?

and will the 4" cinder blocks be strong enough??
I have seen the MHA pizza party where they use cinderblocks for their oven
http://mha-net.org/docs/v8n2/wildac07b.htm
I could substitute the cinder blocks with the solid ones

I want the base to be easily disassembled in case i need to move it since I might be selling my house I don't know if the new owner would like a big oven in the backyard when the time comes.. just in case

and... almost forgot can I get away with the cement pad completely??
I have good compact soil

[Unofornaio]

Re: stand question

so I "decided" to stack 3 rows of cinder blocks (24"), 4x8x16 blocks instead of the concrete pour (4") topped with duroc (1/2") and a final vermiculite cement pour of 5" for a total height or 33 1/2" here's the question
are there any structural issues using 5" of vermiculite since it's so spongy ?
>>>yes, the vermiculite mixture cannot serve a structural role in this manner. Its strength is only in compression.

and will the 4" cinder blocks be strong enough??
I have seen the MHA pizza party where they use cinderblocks for their oven
MHA News - 2007 Meeting at Wildacres
I could substitute the cinder blocks with the solid ones
>>> the block will hold the weight but these are temporary ovens built for demonstration only not long term life.

I want the base to be easily disassembled in case i need to move it since I might be selling my house I don't know if the new owner would like a big oven in the backyard when the time comes.. just in case
>>>>building this way will ensure that the entire thing will crumble when and if you need to move it, the vermiculite just doesn't have that kind of strength.

and... almost forgot can I get away with the cement pad completely??
I have good compact soil
>>> I do not understand what you are asking here. Do you mean "Footings"? or the "Slab on grade" that all of this would rest on?

If your goal is to have the oven "movable" the oven dome itself MUST be built on something structurally sound and able to take the movement that will undoubtedly occur when moving with a forklift or crane. Do you HAVE to use concrete? Probably not, but the alternatives are much more expensive. Even if you used 1 1/2" engineered plywood under the hearth blocks which is gonna cost you more than concrete alone. Then you have the additional steel support which is even more. On top of all this the fact of the matter still is that when you get under this thing to move it every single element that comprises your proposed hearth base will move in its own way. Ultimately, probably before you can get it in the air, the base will crumble and since the base is holding the oven ..well you get the pic.
Based on time, effort and money the slab is the only way to go. Having said that with the proper support under the blocks and a different material than the cement board this proposal would hold up an oven structure but when it came time to move it,forget about it, demo would be the word.

One final note:
Cement is a "component" of Concrete or mortar. Don't sweat it ....its a very common mistake perpetuated by my favorite...DIY shows.

[barbarian]

Re: stand question

yes, the vermiculite mixture cannot serve a structural role in this manner. Its strength is only in compression.[/COLOR]

thanks uno.. just as I thought but I had to ask
but I didn't plan on using the vermiculite and duroc alone, there would be steel across to hold the weight I was wondering if going thicker than 4" is ok with the vermiculite concrete or the dome weight will squish it out and eventually sink in

the block will hold the weight but these are temporary ovens built for demonstration only not long term life.[/COLOR]

again... I thought so I do not plan to disassemble the oven if I don't have to

and... almost forgot can I get away with the cement pad completely??
I have good compact soil
>>> I do not understand what you are asking here. Do you mean "Footings"? or the "Slab on grade" that all of this would rest on?

Yes I meant the concrete slab that the base will rest on

If your goal is to have the oven "movable" the oven dome itself MUST be built on something structurally sound and able to take the movement that will undoubtedly occur when moving with a forklift or crane. Do you HAVE to use concrete? Probably not, but the alternatives are much more expensive. Even if you used 1 1/2" engineered plywood under the hearth blocks which is gonna cost you more than concrete alone. Then you have the additional steel support which is even more. On top of all this the fact of the matter still is that when you get under this thing to move it every single element that comprises your proposed hearth base will move in its own way. Ultimately, probably before you can get it in the air, the base will crumble and since the base is holding the oven ..well you get the pic.

No not movable just easily disassembled that's why I was asking about the concrete (not cement :-) pad/slab that was really my main concern
the oven can crumble down and I can rebuild a better and stronger one kind of like the bionic pizza oven

Based on time, effort and money the slab is the only way to go. Having said that with the proper support under the blocks and a different material than the cement board this proposal would hold up an oven structure but when it came time to move it,forget about it, demo would be the word.

Well I was thinking of putting the vermiculite concrete on top of a 1/4" steel plate I already have one and weld a support with structural steel beams , I have a few sitting around.. if I have enough maybe I can bury 2ft. of the beams in ground and do a concrete pour around it that should be plenty stable and strong, picture a miniature oil rig platform that is definitely easier to remove than a 6x6 concrete slab

One final note:
Cement is a "component" of Concrete or mortar. Don't sweat it ....its a very common mistake perpetuated by my favorite...DIY shows.[/COLOR]

I slipped i swear...

[maver]

Re: stand question

I moved my oven, so here's my 2 cents. First, if access to your yard does not easily allow an 8 1/2 foot wide forklift passage, forget about planning to move an oven. Easily means better than 10 foot clearance. I moved mine with 10 feet clearance and grew an ulcer in a day - do not do this to yourself. Consider also that you need a lot of room to maneuver (at least 30 feet in front of the oven) so if it's shoehorned into your yard please don't plan for that. I lifted my entire slab off the concrete block base - I had pegs of rebar covered with pvc that locked the slab to the base - the rebar easily slipped out of the pvc and the slab lifted up without problems. However, the vibrations that occurred during transit were too much for the dome, so it still needs to be rebuilt.

The slab at the old house can be used for a base for a greenhouse, a hot tub, a pit barbecue. I demolished the block stand and recycled the concrete.

[barbarian]

Re: stand question

I moved my oven, so here's my 2 cents. First, if access to your yard does not easily allow an 8 1/2 foot wide forklift passage, forget about planning to move an oven. Easily means better than 10 foot clearance. I moved mine with 10 feet clearance and grew an ulcer in a day - do not do this to yourself. Consider also that you need a lot of room to maneuver (at least 30 feet in front of the oven) so if it's shoehorned into your yard please don't plan for that. I lifted my entire slab off the concrete block base - I had pegs of rebar covered with pvc that locked the slab to the base - the rebar easily slipped out of the pvc and the slab lifted up without problems. However, the vibrations that occurred during transit were too much for the dome, so it still needs to be rebuilt.

The slab at the old house can be used for a base for a greenhouse, a hot tub, a pit barbecue. I demolished the block stand and recycled the concrete.

No not moving it I wouldn't dare.. disassembling big difference

but thanks for the tip about the slab that is a good solution I'd much rather lift away the whole thing then demolish it

[Unofornaio]

Re: stand question

I was wondering if going thicker than 4" is ok with the vermiculite concrete or the dome weight will squish it out and eventually sink in
>>>No, thickness will not be a factor.


Well I was thinking of putting the vermiculite concrete on top of a 1/4" steel plate I already have one and weld a support with structural steel beams , I have a few sitting around.. if I have enough maybe I can bury 2ft. of the beams in ground and do a concrete pour around it that should be plenty stable and strong, picture a miniature oil rig platform that is definitely easier to remove than a 6x6 concrete slab
>>>As I see it you really have a trade off of time and materials here. Doing a platform as you mention would require a the posts in a frost proof footing on each corner and then an angel brace from post to the middle of the span on each side and something in the center of the square/rectangle as well.

This contrasted it time and material cost with pouring a slab or footing in an "H" and just dry stacking block to support the steel plate. The concrete required to do either the steel posts or slab/footing is going to be pretty close. Depending on you source of steel this may be more cost effective. In addition you would have a cleaner appearance of the base rather than a exposed matrix of steel.

Whatever method you choose the foundation you build on especially in your area must not be built in a "temporary" frame of mind. The weather conditions and soil make up may ultimately decide to hold for a shorter term than you need it to, then what?

To wrap this up, in theory and practice what you propose is possible the question as I see it is, will one or the other (my proposed way or yours) be more or less effort and cost?

[barbarian]

Re: stand question

[QUOTE]

I was wondering if going thicker than 4" is ok with the vermiculite concrete or the dome weight will squish it out and eventually sink in
>>>No, thickness will not be a factor.

good to know as I wanted a shorter base I can make up 1 " with the vermiculite concrete and pour it at 5" instead of 4"

>>>As I see it you really have a trade off of time and materials here. Doing a platform as you mention would require a the posts in a frost proof footing on each corner and then an angel brace from post to the middle of the span on each side and something in the center of the square/rectangle as well.

yes pretty much.. that's it

This contrasted it time and material cost with pouring a slab or footing in an "H" and just dry stacking block to support the steel plate. The concrete required to do either the steel posts or slab/footing is going to be pretty close. Depending on you source of steel this may be more cost effective. In addition you would have a cleaner appearance of the base rather than a exposed matrix of steel.

I guess you're right about the amount of concrete needed if not the same it's pretty close , I have the steel so it would be more cost effective but
if I carefully add other material that I would use to cover the steel frame it probably doesn't make much sense

Whatever method you choose the foundation you build on especially in your area must not be built in a "temporary" frame of mind. The weather conditions and soil make up may ultimately decide to hold for a shorter term than you need it to, then what?

To wrap this up, in theory and practice what you propose is possible the question as I see it is, will one or the other (my proposed way or yours) be more or less effort and cost?

Back to reality.. that's why I like this forum so much .. I will stick to the concrete slab days are getting chillier in upstate NY so the extra mixing will keep me warm and fit