Chimney Help

[alexi82]

Hi Guys,

Hope this is in the right spot in the forums...

I am about ready to build the chimney in my alan scott style oven. I am VERY confused though...

How do I support the chimney at the front part of it? I can build the arch no probs, then i know the back layer of the chimney sits on the bricks that slope downwards finishing off the dome...but where do the rest go? Does it need a lintel to sit on?

It seems that there isn't much info on this anywhere...

Cheers!

[Tscarborough]

Re: Chimney Help

See my sig for how I built the chimney on my barrel vault.

[alexi82]

Re: Chimney Help

Thanks for that I've seen your site before. Tis a great oven.

Unfortunately it doesn't help me as I have stuck to the Alan Scott design and need to work out how to get the chimney built up from behind the arch upwards...

[Tscarborough]

Re: Chimney Help

I haven't seen his plans. Do you have a drawing of the area you can post?

[alexi82]

Re: Chimney Help

Thanks!

The best pics are on this site

Pizza Oven Construction

I've used this for a guide. If you look at points 16 through 19 it shows where the chimney is being built but still not clear on how it attaches to arch....at least not to me...

[Tscarborough]

Re: Chimney Help

Does your throat have that turn down like the one on your link? Regardless, he built his chimney the same way I did, i.e. it sits on top of the front arch.

[alexi82]

Re: Chimney Help

Thanks for your help with this

Yes it has the turn down, and the back of the chimney sits on that slope. And I get what you are sayin but practically don't know how to bridge that gap behind the arch to build the base for the
Chimney to build up on....if that makes sense

[Tscarborough]

Re: Chimney Help

I looked at it closer. He did NOT place it on top of the arch, so he must have used an angle across the sides (pic 16B), right behind the front arch.

[fxpose]

Re: Chimney Help

I looked at it closer. He did NOT place it on top of the arch, so he must have used an angle across the sides (pic 16B), right behind the front arch.

I agree. That's exactly what looks like he did.

[alexi82]

Re: Chimney Help

ok cool...so do you think he would have run the angle all the way across behind the arch, and then mortared those bricks resting on the angle to the arch?

do you think that in this design that the arch forces the chimeny to start too high? or would it still work sufficiently.

thanks for the help guys, this forum rocks...

[Tscarborough]

Re: Chimney Help

They are called "loose angles" and that is what they need to be: loose. You have to leave room for the differential expansion of the angle iron and the brick. Not much, 1/4" on either side is fine, and the angle iron itself is not mortared to anything, it provides vertical support only.

[alexi82]

Re: Chimney Help

Ok cool, so i did some research on loose angles and that makes perfect sense.

Only question i have is, do i build the bricks up in a stretcher style format, i.e. using all of the lintel, or do I just build it up staggering it in and having a gap..

I drew a crude picture and scanned it (attached). this is the view from the back of the arch...i hope it makes sense. Option 1 is the stretcher style, and 2 is the gap...

[Tscarborough]

Re: Chimney Help

You lay them across the angle.

[alexi82]

Re: Chimney Help

sorry for being such a newbie...

when you say across, do you mean not like either of the diagrams i drew?

or across as in each brick lengthways along the angle, and then a length across the throat of the oven, and then join up the throat and angle bricks...?

[Tscarborough]

Re: Chimney Help

The chimney will be either a square or rectangle, with one side sitting on the angle. Nothing special, the brick lay on top of the angle like they would another course of brick.