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No Steel Throat

 
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Old 01-22-2013, 06:21 PM   #21
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Re: No Steel Throat


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Originally Posted by bytor View Post

At what height will the damper be in relation to the existing opening?

It would seem to me, that as long as the arched opening is high enough, then building the firebox with appropriate back-up, installing damper and smoke chamber would be reasonably straight forward.. Might be tricky making the transition from smoke chamber to flue...
You want to make sure you put the arch or the irons up high enough to fit the damper in. 8-10 inches.

The smoke chamber is built to carry the fireplace flue. Only thing that needs to be installed is the damper, if using a vestal poker, some insulation on top of it, put up a wall to up under the throat.
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Old 01-22-2013, 07:18 PM   #22
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Re: No Steel Throat


So to get this straight (and i think I have) You've built the foundation/ash dump, backup, throat, smoke chamber chimney and have installed the flue liners. Correct?

You have yet to build the box and install the damper and fill in the area between the damper and arch. Correct?

And obviously face

Sao long as the smoke chamber is built I can see how this would work. I just couldn't imagine building a smoke chamber with the backup already built
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Last edited by dom-mas; 01-22-2013 at 07:40 PM.
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Old 01-22-2013, 07:38 PM   #23
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Re: No Steel Throat


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fill in the area between the damper and arch.
Is this the part that has CJKarl asking about having material on top of the damper?
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Old 01-22-2013, 07:49 PM   #24
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Re: No Steel Throat


Quote:
Originally Posted by dom-mas View Post
Som to get this straight (and i think I have) You've built the foundation/ash dump, backup, throat, smoke chamber chimney and have installed the flue liners. Correct?

You have yet to build the box and install the damper and fill in the area between the damper and arch. Correct?

And obviously face
Right. On an exterior chimney code requires 6" on the back wall to the first flue. Transition from laying a 4" block to a clay brick on edge. Build the smoke chamber, pretty much exactly the way the Rumford kit looks like, build it with the 4" wall over the irons and the brick on edge on the back wall. Should have a tall throat to the first flue.

On an interior chimney code requires a full 8" wall to the first flue. Transistion from the 4" block to clay brick. Lay up the back wall, draw out the smoke chamber and slam in bricks to the pencil mark. Cap with slab of 8x18.

Quick and easy.

Last edited by JBM; 01-22-2013 at 07:52 PM.
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Old 01-22-2013, 07:50 PM   #25
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Re: No Steel Throat


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Sao long as the smoke chamber is built I can see how this would work. I just couldn't imagine building a smoke chamber with the backup already built
What do you mean by backup?
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Old 01-22-2013, 07:51 PM   #26
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Re: No Steel Throat


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Is this the part that has CJKarl asking about having material on top of the damper?
No, you need a wall to seal it off and get the 8".
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Old 01-22-2013, 07:53 PM   #27
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Re: No Steel Throat


Should note that all this is parged inside. depending on how I feel I might even hit it with a sponge ...shrug...
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Old 01-22-2013, 07:54 PM   #28
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Re: No Steel Throat


The backup material that the facing stone will tie to. It isn't really necessary for the fireplace since the chimney is 6" or whatever back from the firebox face but since they want the face to go up straight rather than stepping back you have backup material for the face stone
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Old 01-22-2013, 08:01 PM   #29
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Re: No Steel Throat


No the stone is essentially a veneer. You build a real chimney with the block. Full 8" codes are met ect. dont rely on stone to meet your codes.

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Old 01-22-2013, 08:03 PM   #30
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Re: No Steel Throat


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No, you need a wall to seal it off and get the 8".
What wall?

Your damper is installed below the arch correct? So there is space between damper and the intrados of the arch. You need to seal that area with at least 4" if you have 4" of veneer or 8" if you have no veneer
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Old 01-22-2013, 08:05 PM   #31
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Re: No Steel Throat


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What wall?

Your damper is installed below the arch correct? So there is space between damper and the intrados of the arch. You need to seal that area with at least 4" if you have 4" of veneer or 8" if you have no veneer
Right, were saying the same thing,
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Old 01-22-2013, 08:10 PM   #32
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Re: No Steel Throat


Right, and I think that is what Karl was wondering about. The small amount of volume being carried by the damper

And I agree. While you CAN include the veneer as part of the fireplace it is better not to use it as part of the 6 or 8" since you never know if someone will tear it off later to drywall it or put up some tile or thinstone of some sort.
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Old 01-22-2013, 08:55 PM   #33
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Re: No Steel Throat


so really you are saving maybe 6 hours labor doing it this way. I understand the way you built it I dont care for the seal around the damper. I usually have to fight for room due to space to get the damper in. I could just see trying to build the box and holding a damper up fumbling around and trying to squeeze inside the box all a big pain in the ass.
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Old 01-22-2013, 09:04 PM   #34
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Re: No Steel Throat


Probably 6 hours, i dunno. I can slam in a throat in an hour. It takes me till 2ish to do the fireplace and clean up. I dont think I could be at the same place on a chimney with the same 7 or so hours doing it the other way.

Plus some of the time im doing the face on a rain day.
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Old 01-22-2013, 10:21 PM   #35
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Re: No Steel Throat


for me usually box back wall and fill with damper in place ash dump cut in cold air etc usually the first day throat and all block work for first floor done on day two with a few feet of tile depending on lay out size etc.
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Old 01-23-2013, 05:06 AM   #36
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Re: No Steel Throat


I'm not so sure that this exact method would work for us after all...

We ALWAYS build our throat/smoke chambers out of 2-1/2" firebrick and refractory mortar....and would rather have this material bearing on the properly bonded 'fill' around the firebox rather than having to try to tie it in to the chimney structure for 'temporary' support. I understand that proper support can be achieved with proper corbelling etc... just not my preference.

What I would like to explore though, is raising the height at which you have your arch (or lintels) JBM, to something like 7 or 8 feet, leaving enough space so that ALL of the guts of the fireplace can be built later. So essentially we would have the block column with flues. The Smoke chamber would then be built up under the flues to provide the permanent support.

It's the temporary support of the flues that has me stumped.

I have seen some rough-ins done like this with the bottom flue encased in a 'collar' of concrete to lock it in place, not a great idea in my opinion... although I wonder about casting something out of refractory that the flue could sit on top of rather than pass through...

Hmmmm....

P.S. we also use custom made flat dampers as opposed to the Vestal brand, and would need a little more 'access' for the installation...

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Old 01-23-2013, 04:31 PM   #37
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Re: No Steel Throat


Bytor,


We build our throats with block first and add our firebox later by taking the block up approx. 16 inches higher than the firebox and then crossing the opening with a masonry lintel stood up on edge and then a row of six in deep solid slabs on top of that and then another masonry lintel laid flat. This gives you a inside ledge of 4 inches to build what we call a jug. We dry lay four to five courses of 4 inch solid block on the inside edge of the lintel and then scribe a line from the box opening below to the desired flue size above. We then cut block and lay and repeat same process on back wall. Then we cut 4 foot masonry lintels into 2 foot lengths and lay up the sides of the throat. After building the throat we lay 4 inch block up the face of the lintel for the veneer to be attached or whatever. The flue can be set right after the jug is complete. This method is extremely fast and offers a smooth slope and is much stronger than corbeling in my opinion. When we install the firebox later we have plenty of room to install the damper and then fill the gap between the damper and lintel with firebrick. Next time I do one I will take pictures.
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Old 01-23-2013, 06:22 PM   #38
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Re: No Steel Throat


Really, form and pour the hearth, run fresh air intake, layout and build inner hearth in a shiner position, and build firebox in a stretcher position in less than a day. You're pretty fast
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Old 01-23-2013, 07:35 PM   #39
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Re: No Steel Throat


Bytor I get what your saying. Ive forensically looked at how you build your throats, and it is better for sure. The throats I build are supported off the interior walls of the chimney, just like you use the fill , i use the walls. Semantics I suppose. With a flue in the cellar something has to be bridged across to start the throat, but when filling the firebox that side is built to support the wall that tucks up under this. Again this is supported.

The corbelling to 8" off the iron or arch, one way or the other it has to be corbeled out whether its off the front of the firebricks or off the angle iron, either way the irons span into the masonry chimney. I always build 8" cheeks on the sides of the chimney, if I were to use an iron it bears on the inside 4" here.

From looking back at your throats I forgot how you taper in at the top of the firebox, that was one of the details I liked, it replicated the rumford throatr. Im not sure how you would implement this with my design. It might be tough as once im at the top of the firebox, im done and setting the vestal damper.

As far as building the entire smoke chamber with firebrick, I just came from your site and the smoke chamber you build is what it looks like on mine, prettier for sure, I top the corbel with a slab off an 8x18 and parge the inside.

Except for the issue at the top of the firebox and how you would make your damper work, I could make our throat meet your criteria for build quality.
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Old 01-23-2013, 07:41 PM   #40
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Re: No Steel Throat


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Really, form and pour the hearth, run fresh air intake, layout and build inner hearth in a shiner position, and build firebox in a stretcher position in less than a day. You're pretty fast
I dont know if he meant all that, I cant tell.

I did labor for a crew that would throw up the base, sprinkle mortar or portland powder on the hearth and start on the firebox. 2 guys would be up to the roofline on the first day and the guy who did the cellar/poured the hearth/started the fireplace would finish the fireplace the next day and the 2 on the staging would finish the chimney by 3.

2 Day chimneys week after week with steps being built as the truck was loaded. 75 chimneys a year no problem. All with angle irons supporting the throats.

Of coarse this was with 8 pitches, 8x12s, 20" chimneys, no partition walls.

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