# rumford damper



## dom-mas (Nov 26, 2011)

I'm doing my first true rumford (superior throat, smoke chamber and damper) and I'm a bit confused about what holds the damper down. It looks like the damper sits entirely within the smoke chamber so there is no material holding it down. Is the HTC the only thing "gluing " the damper down? Continuous pushing up on the damper door will surely pop it after a while


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## JBM (Mar 31, 2011)

Order the other damper. It allows for full opening.


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## dom-mas (Nov 26, 2011)

too late, damper is bought, paid for and should have been installed late today, but I wasn't sure so I came home to ask you guys how to keep it down


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## JBM (Mar 31, 2011)

I was very unhappy with the partial opening of the damper when using the latch that is part of the damper system now. Im not sure how to circumvent that. as far as keeping the damper down, just mud the flange down. 

I have never had one come loose from normal wear and tear, but a pal of mine did call me last year because a chimney sweep cleaned 2 newly built Rumfords, they only had 1 winter of burning in them. anyhow, the friggen moron knocked both dampers loose with his brushes. The house was a cape with a dormered 5 pitch back and god forbid he gets on the roof and cleans it from the top down. Idiot.


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## dom-mas (Nov 26, 2011)

Yeah mud is enough to hold it down? On a traditional FP I have angle iron across the damper with roxul in between and then have the smoke chamber built on top, lots of weight to keep it down. 

Do you just use HTC or do you throw some type S on top as well?


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## JBM (Mar 31, 2011)

It would be applied kinda thick, I parge the top of the firebox smooth with mortar, smooth over the lip of the damper with it too.


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## JBM (Mar 31, 2011)

If I were to do another one I might install a hook of some sort to rest the bottom of the handle on so it could be opened all the way. Or order the other damper.


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## dom-mas (Nov 26, 2011)

Thanks JBM


I'm minorly concerned. The damper that came only stays open when it's fully open. I guess I'll see what's up tomorrow


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## dom-mas (Nov 26, 2011)

As an aside, does anyone ever put up one of the superior chimney pots? The HO asked me to price adding one to the chimney. It seems like a basic install but never having seen one let alone install one I'm looking for tips on how to price it.


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## dakzaag (Jan 6, 2009)

For the Pot, the following applies

Set it and forget it...:thumbsup:

bevel high strength cement around the base as high as you can get it to stand, which really is a function of the base it sets on, but if you get 2-3 inches, it will hold.

Easy as 123.:clap:

For the damper, I am a little concerned about mortaring in the frame. I usually put fiberglass insulation on top of the flange to allow the metal to expand and contract with the heat cycles. If it is locked in, I could easily see a crack developing somewhere. Where exactly the crack would be, I cannot say, but Murphy's law would suggest that it will be in a critical location. 

Since a Rumford throat is slightly different in design, the damper location may require some deviation of the above description, but you cannot ignore the fact that metal expands and contracts much differently through the heat cycle than masonry.


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## JBM (Mar 31, 2011)

dom-mas said:


> Thanks JBM
> 
> 
> I'm minorly concerned. The damper that came only stays open when it's fully open. I guess I'll see what's up tomorrow


Did your damper come with a little bracket to install under the curved throat? That little bugger when hooking the handle is what keeps it from slamming shut, and also keeps it from opening all the way. Im not sure if I like it.


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## dom-mas (Nov 26, 2011)

JBM- No, no bracket, just a flat piece of cast iron with a door the shape and size of the throat opening and a rod. When the door opens fully, it sets down and stays open, you would have to lift it slightly then lower it again

Dakzaag- the rumford smoke chamber is huge compared to the damper. There will be no material to set on top of the damper flange so I can't put any insulation/bond break anywhere. Like I say, first time using the kit and first time doing a true rumford. It's a bit different. Also first time doing a herringbone firebox. Things I'll do WAY different next time.


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## dom-mas (Nov 26, 2011)

Oh and thanks form the tip about the pot Dakzaag. I figured it was pretty simple but just wanted to make certain


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## stuart45 (Oct 7, 2009)

I usually build pots into the stack, especially the tall ones.


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## dom-mas (Nov 26, 2011)

damper opens fully. No obstructions, although I did have to keep mud away from where the "hinges" were or it wouldn't have been able to open. There was no casting name on the damper, just 24.

I was a bit surprised at how big the smoke chamber was. I mean I always knew the dimensions but it just never occured to me that I'd run out of room because the rumford is so shallow.

I wanted to build the chimney out of 6" block because I hate laying 4" and laying brick would cost at least $25/ft of chimney in materials as opposed to less than $8/ft using block. Had to get a pallet of 6" returned in exchange for 4". Sucks because the stone is between 3.5" and 5.5 " thick. I was counting on having some room to work it


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## dom-mas (Nov 26, 2011)

stuart45 said:


> I usually build pots into the stack, especially the tall ones.
> View attachment 93955
> 
> 
> View attachment 93956


Looks like I may need 1 less flue tile as well


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## JBM (Mar 31, 2011)

dom-mas said:


> damper opens fully. No obstructions, although I did have to keep mud away from where the "hinges" were or it wouldn't have been able to open. There was no casting name on the damper, just 24.
> 
> I was a bit surprised at how big the smoke chamber was. I mean I always knew the dimensions but it just never occured to me that I'd run out of room because the rumford is so shallow.
> 
> I wanted to build the chimney out of 6" block because I hate laying 4" and laying brick would cost at least $25/ft of chimney in materials as opposed to less than $8/ft using block. Had to get a pallet of 6" returned in exchange for 4". Sucks because the stone is between 3.5" and 5.5 " thick. I was counting on having some room to work it


Yes keep an eye on those hinges. Also with 4" block, well any block really, if you hang plumb lines you dont need a level but maybe every 2 or 3 feet. Keep the edges straight with the plumb lines and slam those puppies in. In the day I could go from the hearth to the roof in a day on an inside chimney. Stucco and sponge it when your done :thumbsup:


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## dom-mas (Nov 26, 2011)

damn, it took me 2 days to do the herring bone firebox. No helper (he's been weird sick for over a week) and 4 compound angles to cut per course and 2 other cuts. add crawling through a window to make the cuts, a bunch of thinking and some log guys inside a 16'x 20' addition because it's been raining for pretty much 2 weeks and ughh. Slow like dry snot


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## dom-mas (Nov 26, 2011)

Ok, for the clay pots, the one he chose (hampshire) is a base ID of 16", my flue tile is 13x13. Should the flue tile go up until it hits (or comes close to)the pot? Or should the pot start just a couple inches lower than the top of the flue? 


Also does the pot count as chimney height? The chimney goes out center of the roof and it's more than 20' away from any other wall so I was planning on bringing the chimney up 3' past the peak, nice open area tree line is several hundred feet away and it's open to the prevailing winds. The pot is 32" high. I'm pretty sure I'll bring the chimney up the 3' still, it would look weird if it was lower. Also if someone ever changes their mind and doesn't want the pot the chimney is still legal. I think that's good thinking?


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## JBM (Mar 31, 2011)

dom-mas said:


> damn, it took me 2 days to do the herring bone firebox. No helper (he's been weird sick for over a week) and 4 compound angles to cut per course and 2 other cuts. add crawling through a window to make the cuts, a bunch of thinking and some log guys inside a 16'x 20' addition because it's been raining for pretty much 2 weeks and ughh. Slow like dry snot


I lay the 3 walls out on the floor and pre cut everything. It is a lot quicker.

All my fireplace I do like this. The ones with the angled back, laid out on the floor and the helper cuts them.


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## dom-mas (Nov 26, 2011)

JBM said:


> I lay the 3 walls out on the floor and pre cut everything. It is a lot quicker.
> 
> All my fireplace I do like this. The ones with the angled back, laid out on the floor and the helper cuts them.


Yeah, I'm going to do that next time. Cutting and figuring compound angles is stupid slow. And they aren't always perfect. Doing panels is the way to go for sure


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## JBM (Mar 31, 2011)

dom-mas said:


> Yeah, I'm going to do that next time. Cutting and figuring compound angles is stupid slow. And they aren't always perfect. Doing panels is the way to go for sure



I did one in Florida for a guy and he laid them on wire mesh with tar paper behind it. Next day cut the panels and grouted the joints with a bag and the 3rd day we picked them up with a dolly and set them in place. Was pretty slick, although im not sure how I feel about the mesh being inside the firebox.


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## dom-mas (Nov 26, 2011)

Yeah i remember you talking about that in artisanstones thread. Buckleys website recomends panels as well. So much more consitent and you aren't fighting gravity all the time, propping up brick with a stick or bucket. 

Hopefully I get to do another one before I forget all this junk


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## stuart45 (Oct 7, 2009)

dom-mas said:


> Ok, for the clay pots, the one he chose (hampshire) is a base ID of 16", my flue tile is 13x13. Should the flue tile go up until it hits (or comes close to)the pot? Or should the pot start just a couple inches lower than the top of the flue?


Never had this problem, as our pots are designed to sit on top of the liners with a spigot fitting.
It's normally better for flue gases to go into a smaller area to speed them up.


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## artisanstone (Nov 27, 2007)

With fireboxes, I see three options.
1. precut on the floor or panelize by some means.
2. build it in place conventionally. mark each cut and have your labor running back and forth.
3. build the two side walls in place and cut the angle the next day. I've not done it this way, but I think it would work in certain situations.

I think it would be best to know every way, and use each one as it fits. The main factor on these is scheduling. On our job it made sense to build panels to streamline production, but each job would be different.

I will say with the panels, we've had to go back and repair cracking in the vertical joints where panels meet.

On the chimney pots issue, I imbed them a little (2-4"). I wouldn't worry about them going anywhere though. If you imbed them too far, you change the visual proportions. If they were completely on top, some nimrod chimney sweep might grab hold and hurt himself.


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## dom-mas (Nov 26, 2011)

For JBM, this is a pic of the damper. It seems to function just fine. Opens, closes.

Edit, i painted it black with exhaust manifold paint. Cured in my engine compartment. It was outside for 2 days and was totally rusty so I figured it needed some paint. Hopefully it lasts


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## JBM (Mar 31, 2011)

Cool!


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