The hearth questions and progress pictures

[Dutchoven]

Nice brick and stone work George
Dutch

[asudavew]

Originally Posted by George T

More progress on the fireplace today. Tomorrow I get to work on the WFO again. I also need to begin thinking about the chimney structure. I was thinking of going with a masonry flue tile, but I have to angle it back to get to the center of the structure. Not sure how I would provide the appropriate support for a complete masonry chimney....perhaps the Stainless steel would be better route to go.....lighter weight and require less extensive support. Anybody helped someone through this issue before?

Picuture updates below.

Just check out my thread.........
I went with a light weight chimney.
But... I have recently covered it with high heat mortar for a better draw.(fingers crossed)

[dmun]

I was thinking of going with a masonry flue tile, but I have to angle it back to get to the center of the structure. Not sure how I would provide the appropriate support for a complete masonry chimney.

I worked through this with my project, which has a two story two flue masonry chimney. What I did is to angle my flue tile back at 30 degrees until it was at the correct position for where I wanted the chimney to be. At this point the angled flue tile is supported by mounded up vermiculite concrete. When I got it to the place where I wanted it, i poured a support slab, basically a re-inforced concrete bridge, with vertical supports to the main hearth slab. I put a layer of insulating blanket around the flue tile before I poured the slab, so it wouldn't bind and stress the dome at that point. Up from there, I stacked up the flue tiles with refractory mortar, and built the chimney up from the secondary support, with the required min 1/2 inch air space around the flue tile.

I gave the process a lot of thought, and that's what I came up with. It may be a tad overbuilt, but a masonry chimney is a lot of weight.

[George T]

Dutch. Thanks for the compliment. My nephew is a brick mason and I grew up working for my dad....also a mason....They do the real skill work.

Thanks dmun. I will have to try to track your pictures down to get a better idea. I am a bit pressed for time and I keep thinking although more expensive I might be better off to go with a duratech solution. Do you or anyone know if the straight lengths of the pipe can be cut to length or do you have to piece together based on preset lengths.

I was also was thinking about using single or double wall stove pipe....there are no combustibles and it is less expensive.....Thanks again everyone for your thoughts

[asudavew]

Hey George,

I just finished up my chimney. I'll post some pics in a bit.
Basically it's a thin gauge metal pipe with a rectangular transition that I wrapped in chicken wire, and covered with high heat mortar. I just covered most of that with perclcrete insulation.

I think it turned out nicely and cost me... 25-30 bucks.


Dave

Oh.. I bought the pipe and transition at H/D

[stewpot]

George
I really like how your oven progresses
I am about to pour the concrete/vermiculite but seeing your photos I may go back and remove the top course of 9'' blocks, and replace with a course of 4''.
I was wondering how to protect the layer of vermiculite from the weather, this would solve the problem. Seems to be a lot of extra work,though.
Replacing the top course and pouring the base inside would reduce the height 9'' which may not be a bad thing as I,m going to finish up with oven floor at about 4'6'' as it is at the moment.

[George T]

Originally Posted by stewpot

George
I really like how your oven progresses
I am about to pour the concrete/vermiculite but seeing your photos I may go back and remove the top course of 9'' blocks, and replace with a course of 4''.
I was wondering how to protect the layer of vermiculite from the weather, this would solve the problem. Seems to be a lot of extra work,though.
Replacing the top course and pouring the base inside would reduce the height 9'' which may not be a bad thing as I,m going to finish up with oven floor at about 4'6'' as it is at the moment.

I still plan to run 4 inch block up to full height as we move forward with the enclosure, so when I put my loose insulation in I should be good to go....it was nice to not have to form it up. instead using the block as the form. I just closed off the front.....

[stewpot]

Thanks George
I now plan to concrete to surround the insulating layer, then infill with vermiculite/cement. The final enclosure (yet to be ''designed'') will rest on this 3-4inch outer edge with a small landing at front.
what is the insulating board I read about? does anyone know if it's available in UK.
Your workmanship makes my effort look very amateurish
regards
Stuart(Stewpot)

[George T]

A good weekend for progress. Was able to get the chimney opening setup. Thanks Dmun for the advice. Next weekend hope to actually start putting the flues up.

For final insulation can I just fill the cavity with Perlite? Do you recommend the blanket plus perlite? I have access to perlite.....$16 for 4 cubic foot bag.

Here are the pictures of the progress.

All Pictures on Picasa.

Picasa Web Albums - George - George T's Pi...

[George T]

Originally Posted by stewpot

Thanks George
I now plan to concrete to surround the insulating layer, then infill with vermiculite/cement. The final enclosure (yet to be ''designed'') will rest on this 3-4inch outer edge with a small landing at front.
what is the insulating board I read about? does anyone know if it's available in UK.
Your workmanship makes my effort look very amateurish
regards
Stuart(Stewpot)

Stuart. Thanks. The board People are talking about is an insulating board. You can read more about it on the website in the store. I chose not to use it do to cost and availability. You also asked a question regarding protecting the perlcrete. We cover it up every day with a tarp.....try to keep it as dry as possible. I don't think a little water would hurt it. I was more worried about the clay/sand mixture under the bricks....if we got a massive down pour.