# I need fireplace help



## artisanstone (Nov 27, 2007)

I know I've seen it mentioned before by some of you northerners, but can someone explain how to build a fireplace/chimney without the firebrick?

Situation: firebrick is special order from France, and the builder needs the rough-in done now. I'm not sure how you would support the damper, or does that go in later from below?

TIA for the help.


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## JBM (Mar 31, 2011)

I put the damper ontop of the firebox when I build it, usually after the chimney is done. 

I use 2 angle irons or an arch form I have kicking around. Ill see If I can grab a picture, but you need to set the first angle iron with enough height to slide the damper ontop of the firebox, 6" is tight.


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## artisanstone (Nov 27, 2007)

A picture would be good.

My thought was to set the damper on corbeled brick, and do everything except the firebrick. This is a slant back, so do you do the corbeled backup beforehand, or???

Just trying to wrap my head around what's possible. I don't even know the firebrick size yet. I know they want diagonal herringbone, and we're supposed to start Monday.


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## JBM (Mar 31, 2011)

I line my chimney with 4" blocks and build off of those. 

Here is a picture showing the corbel on the angle iron, just happens I built the fireplace first but the method I use is the same.


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## JBM (Mar 31, 2011)

If its a 24" chimney youll do a brick on edge against the outside wall building off the 4" block, if its 28 then just use a brick 4" ect.


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## JBM (Mar 31, 2011)

When you build from the top of the firebox to the bottom of the angle iron, when you build the fireplace, youll have to build a wall on top of the damper to seal it off. I stick insulation on top of the damper for expansion against the face.


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## JBM (Mar 31, 2011)

artisanstone said:


> A picture would be good.
> 
> My thought was to set the damper on corbeled brick, and do everything except the firebrick. This is a slant back, so do you do the corbeled backup beforehand, or???
> 
> Just trying to wrap my head around what's possible. I don't even know the firebrick size yet. I know they want diagonal herringbone, and we're supposed to start Monday.


I fill my firebox as I build it, since its at the end of the chimney usually, I fill it with broken stuff from under the staging. Since its lined with 4" blocks it just needs to be filled loosely with some mud plopped in there strategically .


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## artisanstone (Nov 27, 2007)

OK, so when you are building the rough-in, before you do the firebox, at what level are the two lintels crossing over to support the front of the chimney? I assume they are back to back a little higher than the top of the damper?


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## JBM (Mar 31, 2011)

artisanstone said:


> OK, so when you are building the rough-in, before you do the firebox, at what level are the two lintels crossing over to support the front of the chimney? I assume they are back to back a little higher than the top of the damper?


If the top of the firebox is say 40 then ill set the irons at 48". 

I set one iron and do a course over it. Then ill either hammer cut or use the chop saw and make angles like 4 1/2-6 1/2. Ill lay the next course like the first one that was across the angle iron. 

So you have brick course, header course that was hammer cut and single brick course on top of that. (do those at the same time to keep them from tipping. ) So now set the next angle iron on the front of the hammer cut brick. Lay a course on it, now tie them together with a header course. 5' chimneys use a 4' angle, 6 is 5 and on and on.


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## artisanstone (Nov 27, 2007)

I made sense of that:thumbsup:

So you end up with 12" wall thickness in 3 courses. All of this set 8" higher than bottom of damper. Correct?

This seems the way to go, mainly because I can build the firebox later without hitting my head too much.


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## JBM (Mar 31, 2011)

Itll be 8". 12 if you add the fireplace "brick" in front of the angle iron courses. 

Its basically 3 courses to grow 8" with 2 angle irons. Tie the top together.


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## fjn (Aug 17, 2011)

A trimmer arch to the rescue ! This excerpt from Richard Kreh explains how to pull it off.


https://books.google.com/books?id=4...v=onepage&q=richard kreh trimmer arch&f=false


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## artisanstone (Nov 27, 2007)

An arch is certainly the elegant solution. Any worries about the cold joint between arch and masonry below it that's built later? 

I guess the same question would apply to JBM's method, but his has the advantage of a "Z" shaped break in the cold joint.


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## fjn (Aug 17, 2011)

artisanstone said:


> An arch is certainly the elegant solution. Any worries about the cold joint between arch and masonry below it that's built later?




I would not let that be a concern,relieving arches have been built for centuries, trimmer is just another aspect of a relieving arch.


https://www.google.com/search?q=rel...lZTLAhWJSRoKHZWaBRgQ_AUIBygB&biw=1093&bih=514


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## JBM (Mar 31, 2011)

artisanstone said:


> An arch is certainly the elegant solution. Any worries about the cold joint between arch and masonry below it that's built later?
> 
> I guess the same question would apply to JBM's method, but his has the advantage of a "Z" shaped break in the cold joint.


Youll want to keep either the arch or angles as low as you can but still get the damper in, that way you have a few courses to seal off. 

An arch is better, I have mine made so i can do a taper in it, but you can go right to 8" as long as the damper door opens. 

When we used to build with 2x4's and keep the fireplace flush this was not really a concern. With 2x6s and keeping the face off the wall it moves the damper way the frick out and there is concern it will hit, hence the sharp angle in my pic.


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## JBM (Mar 31, 2011)

Add to that the inspectors want 1" clearance against the house in the throat area now too!, not easy anymore.


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## artisanstone (Nov 27, 2007)

That is not a real concern in this case. I should have mentioned it before, but it's back to back fireplaces. One 36" flush hearth, and one 48" raised hearth. The overall fireplace/chimney structure is pretty big, so lots of room to move things around. I think they have the 48" fireplace drawn at 2'9" deep


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## JBM (Mar 31, 2011)

Do you have a link to those firebricks from France?


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## artisanstone (Nov 27, 2007)

No, I found out Thurs. that the designer is supplying them. I still don't know the size, so we may not get much done on Mon.

I will try to take some pictures of the progress.


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## dom-mas (Nov 26, 2011)

Please take as many progress pics as possible. Particularly where you start and stop on the smoke chamber. I'm having a hard time wrapping my head around it without pics.


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