Need some fireplace flue advice

[3584ELK]

Let me build the scenario, then I will ask the questions and let the experts tell me what to do!

We live in a bi-level home built in 1980.  The home came with a fireplace in the upstairs living room.  On the opposite side of that wall is the garage and the flue box goes up and out the roof.  The flue box at the roof opening is roughly 2 feet wide and 3 or 4 feet long. 

At some point in the past, some idiot installed a wood burning stove downstairs, directly below the existing fireplace.   Instead of routing the stovepipe up and around the fireplace upstairs and on up the flue box, he cut a 12" hole in the bottom of the fireplace and poked the stovepipe right through the middle of things!  Well, we want to move the woodburner from the middle of the wall over to the corner (about 6 feet).  I would like to see the fireplace functional again, but not sure where dear wife is on that subject.  A contractor once told me the fireplace was ruined and we would never be able to get it sealed and usable again.  This seems odd to me since I have built firewalls for aircraft engines with temps in the 1500° range.  This was accomplished with stainless steel.  But I digress...

Do you think its feasible to save the fireplace?
If so, how?
When I move the woodburner, I propose (in my head) to angle the new flue box towards the old one at a 45° angle and then continue upward.  Does this make sense?

Any opinions, discussion, help would be much appreciated.  I hope I painted a clear enough mental picture.  If not, I will try to post some pics to help.

[beenthere]

Some pics, and some drawings, if possible would help. Seems to me, given what you have said, that the fireplace could be fixed. At least the 'floor' of the firebox could be re-bricked after filling in the concrete removed below. Now, the damper may be another headache, depending on what was done to the old one to get that pipe shoved through there.

Seems the important part is to seal the new firebrick well with fine mortar.
Then run a woodstove flue up beside the existing fireplace flue in the same chase.

But to keep this on track, pics would help. 

[etat]

Regular mortar is not rated for the heat of a fireplace.  Be sure to use a firebrick mortar that is.  (I 'beleive' i'm right but I'm not near a expert)

[UNCLEBUCK]

I asked my pops and here is what he said to me , check the insurance company, the fire code,  patch the hole with regular cement or the kind ck says because heat goes up , lay down those 4x8x1 inch thick firebrick all around the fireplace interior or just the bottom for sure , or just a piece of 1/4 inch plate steel for a fireplace bottom over the cement patched hole and youre back in business. Anything concealed has to be stainless steel so you could go architectural stove pipe down below exposed until its time for the pipe to be concealed going up then switch to stainless. I guess that architectural stove pipe is a common thing at any fireplace showroom .I aint never herd of dat goofy stuffs  I hope this helps and good luck

[solodan]

also check to see if the fireplace damper has been cut out to fit the stove pipe into the flue. lots of times in order to get double insulated pipe to fit into the opening, a layer of bricks and the damper must come out. another option would be to install a wood insert into the fireplace, less effecient than a frre standing stove, but way more efficient than a fireplace.

[Weekend_Sawyer]

 Some of the bricks in the back of my fireplace had come loose. I can still remember my Dad telling us kids,
"Don't throw that wood in there, you will knock the bricks loose. Dad is gone now and I own the house and after all these years it did.

 I went to my local brickyard, a man who has been in business a long time, told him I needed high temp mortar and why. He told me that I only needed regular mortar as the high temp is only for industrial uses.

 I bought a bag of regular stuff from him, pointed up my bricks and am on my 4th cord this year with no problems.
I am keeping my eye on it.
I am placing my wood in it instead of throwing it.
I am toasty warm.

It was 17 deg this morning.

Jon

[3584ELK]

Thanks guys!  I knew I could get some good advice here.  Tonight I will shoot some pics and upload them for your perusal.   

I realize I am probably pushing things by trying to make a "city home" into a log cabin compatible with  woodstove heat throughout, but hey-  its cheap, its fun, and there is great satisfaction gained by doing it myself! 

More later...

[Tom]

Before you hide it all, remember that a lot of heat comes off of exposed chimney pipe before it exits thebuilding.  Lots of old homes will run 10 feet or better exposed to take advantage of it.

[3584ELK]

Well, after cropping the pics once, they are still too large.  I give up.  Maybe tomorrow I will feel like messing with it some more.

[DanG]

358, are you using the xat.com optimizer?  If so, after you crop and rename your image, close the little window where the pic is.  Then reopen it and you'll have the new, cropped image to work with.  It will reopen with the crop menu.  Look on the left side and you'll see a bunch of buttons.  Find the resize button and poke it, and that'll give you the resize menu.  Use the little slide bar to get the biggest side down to about 350, then "save as" again, close and reopen your image and you'll have the compression menu.  Slide that until you're below 30k, save again and you're done.

It takes me about 30 seconds to prep an image to post.

[3584ELK]

Dan,

Thanks, I will have to try that.  I was just aggravated last night. 

[Furby]

Um DanG, there is no need to save the image between steps, just go from one step to the next. You can save it if you want, but don't have to.
I bet you could do the whole process in under 10 seconds.

[3584ELK]

Still no pics, I am so frustrated with trying to crop pix on my home computer, I could puke. 

Anyhow, I had a pretty interesting occurence 2 weeks ago.  Kept getting smoke back into the stove and room.  I pulled the stovepipe, cleaned out the box below the chimney, etc, etc.  Still horribly backed up.  So, I poked around and found the cap on the chimney completely coked up!  I mean, its full of 3/8" square openings, and it was plugged solid!  There was a dark oily, sticky substance all over the outside of the chimney and box.  I am burning lots of spruce, all of which was dead standing, or on the ground last fall.  No greenies, but it must have tons of sap in it.  I have heard of intentionally starting a chimney fire to burn all of it out, but I am a bit scared of that.  Short of climbing onto the roof every month, do you have any ideas?

[Glenn]

I know exactly what you mean about the 3/8 holes plugging up - it happened to me!  I cleaned my wood furnace religiously, it's about 24' long and goes straight through the inside of the house.  It never got really dirty so i was surprised one day when it started backing up.  I cleaned it all out and hardly any dirt came out.  I climbed on the roof and found that the screen was plugged up.  It does this becasue this is the coldest part of the chimney and this is where it creosotes up.  I took the screen off and haven't had a problem since then ( several years now).  Aroound here i don't worry about hot embers flying out because snow doesn't burn and it's plenty damp when i start using the furnace.  I foound out later a few other people around the area had the same thing happen and now i watch to see how many screens are on chimneys - not many around here!

[Ironwood]

On the flue build up, scour it out with a good chimney brush. Are there flue liner clay tiles on the inside? Make sure it is not single walled brick! I slid a 20' top of the line stainless liner in my single walled 1915-1920 brick chimney(nothing  but the best when dealing with fire hazards) I have a large Vermont Castings in the kitchen. Burn good wood and keep it hot, which shouldn't be too much trouble asa you cant choke the air to a fireplace . If you really want efficiency you must put in a woodburner or insert other wise it is totally inefficient abeit pretty.

As to the guy saying you can't fix it. BS I get this all the time when dealing with tradesman used to the same ole same ole. It gets old. I understand they think inside the BOX but geeesh. I get it all the time. blah blah. It can be done and done right. Some good advice before my posting, you'll be fine. overdo it and then, over do it. it will probably be safer than the original. Welcome to life outside the box. Glenn pegged it on the cold part and the build up. Your chimney should be fine as this indicates a thermally efficient chimney (usually on an interior wall) or well lined and insulated. Those end of the house outside wall chimneys never really get a chance to heat up well.

                  Reid

[solodan]

I have heard of intentionally starting a chimney fire to burn all of it out, but I am a bit scared of that.

 
I have also heard that starting an intentional flue fire at initial start up of your stove will keep the flue clean. I have heard that a paper bag at start up helps, and so do dry potato skins. I have not tried the potatoes, but I know the brown paper bag gets hot real quick. My screen used to get clogged up every three or four weeks. I also have a fairly long run of pipe, about 24'.
This year I have a whole new method. I start the fire with alot of dry kindling. I pretty much fill up the whole fire box with kindling and leave the door cracked open and the damper all the way open. The result is the flue gets hot quick, and burns out any of the creosote build up. Burning dry wood prevents build up, this keeps the flue nice and hot.

[mike_van]

The heat from a chimney fire can crack the flue tiles. I wouldn't do it intentionally.   

[Ernie_Edwards]

Our first winter here,'99-'00, was our first heating with wood. Had a cap on the flue which over the winter ended up dripping creosote on the roof and staining the asphalt shingles.After all these years the stain is almost gone.

Anyway, called a chimney sweep and he discovered a big buildup in the flue which took a lot of time on his part to chip away($$).

His reccommendation was to lose the flue cap, which we did, and to use a product called STAGE II, which we spray 1-2 squirts into the firebox everytime we add wood to the fire. It is about $25.00 a gal and we go thru about 3 quarts a winter. Then when he comes to clean the flue there is just the finest ash only in the horizontal duct from the furnace to the flue and nothing in the flue. The last 4 years he said he didn't need to clean the flue, and dosen't charge as as long as there is a fresh cup of coffee to go with something fresh out of the oven.

I am usually very sceptical of any "wonder products" but this one seems to work. Call a local chimney sweep and see if he can get it for you.

Good luck,

Ernie Edwards

[sprucebunny]

Many people recomend starting a fire with 1/2 a cup of diesel fuel in a dixie cup. Vapors from diesel or coal clean the chimney right out... don't know if it works on a screen type cap and I probably wouldn't suggest it for a fireplace.

One year I ran out of wood but had about 1/2 ton of coal in the basement. I unhooked the woodstove and put in a small pot belly coal stove. The first fire ...you guessed it ...all the creosote build up came straight down the chimney and filled the stove. It was glowing red...I thought it would melt 

[shopteacher]

When I first installed wood burning stove (over 20 yrs ago) the seller told me how to get it to burn all day on one charge.  He said to close all the drafts tight after getting the fire started. It did last all day and in the second year I had flames about 10 foot high coming out of the chimney.  It was a single layer of brick with no liners going through the center of the house.  My chimney is now on the outside of the house.
  After that I did quite abit of research on wood burning stoves and the affects of burning wood.  There were and I suspect still is information from a couple of different laboratories that tested burning different species of wood and green vs. dry.
  A couple of things that stuck with me is:
 Greenwood actually creates less creosote than dry, however most of the BTU produced goes to drying the wood as it burns and negates the heating ability. 
   Pine produced no more than hardwoods, however they burn up quickly and have to be replenished often.
   Keeping the flue temp between 250 to 400 degrees produces the least amount of creosote.
   There were many more facts that I can no longer remember, but I haven't had a chimney fire since and don't need to clean the chimney anymore. I used to brush it about twice a winter sometimes more.  That fire scared the be jesus out of me. I can tell you it not a good experience.
    I now have a flue thermometer on each of my flue pipes and when burning wood I get the flue temp up to around 500 deg. for about 15 to 20 minutes daily.  In the fall I clean the ash pit of about a gallon of ash that had fallen to the bottom of the chimney from the previous winter.