Would this work?

[browny]

Hi All,

I've been thinking up some designs based around a pompeii igloo.

I'd really like a brick chimney as it ties in with the style of my house however I'm a little concerned about the load it puts on the structure underneath and since it's and igloo there isn't heaps of room for blockwork to support it all.

My idea, pretty much pinched from rado's builds was to encase the vent area in concrete and then build the chimney on top as per below:



A couple of rebar hoops could be added which could be tied in to the upper slab.

For the chimney I'm thinking a veneer of brick around a stainless liner.

What do you reckon?

Cheers, Tim

[Les]

Re: Would this work?

Tim,

If you build your arch correct - you can put a LOT of weight on it. By design, it's going to put the weight on your hearth. I really don't think you need to do anything special. I dropped steel inside my cores but in hindsight, I don't think it was needed.

[Tscarborough]

Re: Would this work?

An adequately buttressed arch will support an immense amount of weight. Instead of using concrete in tension, as drawn, add more masonry to the lower outer edges of the arch to utilize masonry's superior compressive strength.

[browny]

Re: Would this work?

Thanks.

So just laying a couple of concrete blocks each side might be sufficient?

Ultimate aim is to achieve that shape so I'd need to fill in the top somehow. Would v/pcrete be suitable?

Is there anything special I would need to do in the transition from fire bricks to normal bricks up the chimney?

[Tscarborough]

Re: Would this work?

My chimney is laid on a bed of perlcrete. Most brick are OK for incidental fire contact like in a chimney. I would carry the firebrick up through the throat and transition them at around the level of the top of your dome.

[nissanneill]

Re: Would this work?

Browny,
I don't see any problem as your front arch, side entrance walls and oven opening arch will all share the weight of your brick chimney.
If you still have issues, maybe build your chimney with Hebal or similar and cut tiles from your selected brick and tile the structure.


Neill

[stwater]

Re: Would this work?

He is an idea.

[SableSprings]

Re: Would this work?

Thanks.

So just laying a couple of concrete blocks each side might be sufficient?

Ultimate aim is to achieve that shape so I'd need to fill in the top somehow. Would v/pcrete be suitable?

Is there anything special I would need to do in the transition from fire bricks to normal bricks up the chimney?

As TScarborough noted in his comments, the arch will support a lot of when it is properly buttressed. I added some rebar down my cores (as Les did) just because I'd rather overbuild than rebuild. I've added some thumbnails below to show you my brick/buttress/chimney base, brick weight load on my almost complete chimney system, and the final tie-in & side buttress incorporated into the "barrel facade". It sure looks like your design will work-but I'd add a little more outside support (as you note) since that's where the weight is directed by the arch.

[browny]

Re: Would this work?

Thanks for the help guys.

I'm a little way off building anything yet so can still give it some thought, but a couple of concrete blocks, possibly with some rebar, would fit pretty neatly into the design.