Keep or replace the brick chimney?

[The Drawing Bird]

Ladies and Gents,

I'm hoping to find a masonry expert or someone with experience converting a gas fireplace into a wood-burning stove setup. 

We're renovating our new house, and the current fireplace needs work.  It's not our style (see first picture), and the portion of the chimney that extends above the roof needs repair.  It was set up for a gas-burning stove, but we'd prefer to have a wood-burning stove installed (something like the third picture).  It wouldn't be the primary method of heating the house, but for the coziness.

We've torn down the non-structural parts of the fireplace mantle, and we've found that the brick chimney underneath looks to be poorly built.  In addition, the bottom of the chimney doesn't have an opening... I've never seen anything like this. 

So, my question is should we keep the brick chimney or replace it entirely with a metal flue? Here are my thoughts about the pros and cons of keeping the brick:

Pros

• We don't have to take apart the brick chimney.  It sounds doable, but it would make a pretty big mess. Saving time and effort.
• Probably less expensive, since we could just route a flexible liner through the middle of the chimney instead of buying a double-walled metal flue to go up through the 2nd floor, attic, and above the roof. (from my preliminary research)
• The chimney runs through a bathroom on the 2nd floor.  If we leave it as-is, we wouldn't have to tear down portions of the bathroom wall to take it apart.
• I think the look of a brick chimney is better than a metal one extending from the roof.

Cons

• In addition to repairing the brick up top, we'd have to create some sort of structure to support the weight of the column, so the stove could sit underneath it with a normal mantle opening.  It's not an option to simply place the stove in front of the bricks (like it was with the original, gas stove) because the room is quite narrow and it would impede the flow of traffic.  I'm guessing the load-bearing frame would have to be out of metal, since it'd be close to the hot air... this is currently out of my comfort zone to do ourselves.
• The portion that goes through the bathroom on the second story takes up a considerable amount of space.  I think a metal flue with the walls at the required clearances would take up about half the space.  It would make a big difference in the bathroom.

I'd appreciate any thoughts/tips you have, even if it's just your experiences with wood stoves!  I'll try to keep you updated as things go along.

[lthenderson]

That chimney is designed for wood burning stoves that sit in front of the chimney. But it sounds like you don't want that kind of setup. I don't think anyone in their right mind would ever tear out the bottom portion of the chimney and leave the top untouched or setting on metal beams that aren't already in place before the brick was set on top. I don't think anyone would want to attempt supporting all that weight in a small footprint that also needs room to slide metal beams into place.

I guess the options I see are to tear out the entire chimney and build a new chimney around a wood burning insert meeting code. This would require a lot of work fashioning a chase where the chimney was in the upstairs part of the house. Modern houses do this and the new flue is covered in sheet rock. There are some codes at how close the sheetrock can be used to the opening of the wood burning insert but cement board can be used there and tiled over with veneer stone/brick as your aesthetics dictate.

Less work would be to find a small free standing wood stove to sit in the area where your gas stove sat.
 
Most expensive route would be to rebuild the entire thing out of brick again from the ground up.

[sonofsven]

If it's in bad shape I would take it out. Have you gotten any quotes on the cost of restoration? Or the cost of a metalbestos install?

I like the more modern look of a woodstove with a pipe exiting vertically through the ceiling. No mantle, nothing on the wall, just the code required hearth (floor protection). Like a Jotul catalog ;-)
It can be single wall from the stove to the ceiling and then it's double wall up and out through the roof.

The portion of the piping that is above the roof is also easier to maintain and to flash properly. Brick chimneys are prone to leak at the roof. The roof flashing is embedded into the mortar and over time it breaks down.

I believe it's easier to clean a metalbestos chimney as well. I'm no chimney sweep, but I go up on the roof every year, remove the weather cap and clean it with a six inch round brush with an extension pole. Easy.

I've taken down a few chimneys, it wasn't difficult. Contain the dust, use fans to pull the air/dust to an open window if possible, use plastic to wall in the work area (slightly long 1x2 or equivalent can be bent into place to hold the plastic sheeting to the ceiling).

If it's not a major architectural element and you don't like it then just get rid of it. They're really only for looks these days.

One element in their favor is their value as a "thermal mass" that holds heat, but occasional use wouldn't really trigger that.

One other thing to consider; you can also install a metalbestos chimney in another location if that works better, you're not locked in to the brick chimney location (although the nearly ready made chase is tough too overlook).

[The Drawing Bird]

I don't think anyone in their right mind would ever tear out the bottom portion of the chimney and leave the top untouched or setting on metal beams that aren't already in place before the brick was set on top. I don't think anyone would want to attempt supporting all that weight in a small footprint that also needs room to slide metal beams into place.

Yeah, that makes a lot of sense.  Who knows how stable that column of brick is.

[The Drawing Bird]

The portion of the piping that is above the roof is also easier to maintain and to flash properly. Brick chimneys are prone to leak at the roof. The roof flashing is embedded into the mortar and over time it breaks down.

I believe it's easier to clean a metalbestos chimney as well. I'm no chimney sweep, but I go up on the roof every year, remove the weather cap and clean it with a six inch round brush with an extension pole. Easy.

We had assumed that the longevity/ease of maintenance would be similar for the two setups.  It's good to know that the periodic cleaning is doable with the metal pipes.

Even though I would typically lean toward keeping historic house features, it looks like we're going to move forward with dismantling the brick chimney.  Still waiting on estimates for installation costs.  I'm assuming that the used stove will be in the neighborhood of €500, a wooden mantel for €250, the insulated pipes and connections for €1000, and labor... around €300?  We'll see.

[Fishindude]

It's pretty common to run a new stainless flue inside an existing masonry flue if it is big enough.   This would allow you to leave it in place, just elbow out the top of wood stove and into the side of the flue.

The idea of taking out the bottom part of flue and leaving upper is crazy.   Take it all out if it's that big of an issue to you.
Note - A stainless flue still requires significant clearance around it to meet code, so the actual footprint of the framed / stainless chimney is not likely to be much smaller than the current masonry chimney.

Get a fireplace guy over there before you tear anything else apart.

[The Drawing Bird]

Update:

After looking more closely at how this was put together, our general contractor told us that chimneys around this time were commonly built to be supported by the adjacent brick wall.  They were familiar with bracing the weight at the ceiling of the ground floor, so that's what we went with.  It's a bit difficult to see in the picture, but the portion of the wall with the black stain is where the chimney stack used to sit.  Wood and metal braces are incorporated into the load-bearing beams.

We'll go ahead and finish the floors, wall, and ceiling before we add the stove.

[roomtempmayo]

I'm glad you got a pro out to take a look.

The stove in your last photo is a Morso.  It's a nice stove, but probably 2-3000 Euro new.

Even though I would typically lean toward keeping historic house features, it looks like we're going to move forward with dismantling the brick chimney.  Still waiting on estimates for installation costs.  I'm assuming that the used stove will be in the neighborhood of €500, a wooden mantel for €250, the insulated pipes and connections for €1000, and labor... around €300?  We'll see.

I don't know where you're at with this project, but if the chimney is solid your cheapest option is an insulated liner.

The alternative of a Class A double walled metal chimney is great, but it will cost lots more than your estimates above.  Labor alone on a metal chimney install (at least here in the US) is probably 1000+ Euro, and that's if the installer is providing the pipe and hardware at full retail (2-4000 Euro, depending on height).  Demolishing an old brick chimney/hearth, removing it, and replacing it with a Class A chimney and stove can easily be 10,000+ Euro.

If it were me, I'd drop an insulated liner down that chimney and get a good used Jotul or Morso stove (check carefully for cracks).  You can probably DIY this for <2,000 Euro.  Once you mess with the chimney it will get more expensive in a hurry.