Old House/ New Install (help me)

[benbirby]

Howdy folks,

I need some advice.

**TL; DR -- can I do a 45 to jog over connector pipe before going into thimble?**

Apologies in advance if this is a ramble, will try to include all relevant information.

I am doing a new stove install in a very old house (1880s).
I recently got a new boiler and water heater so my chimney is now vacant. I have a chimney company coming in a few weeks to do some repair above the roofline, install a new liner, cut a hole for the thimble and hook up the stove.

In the meantime......
In the 10 years since I've owned the house I've always wondered what the old fireplace looked like behind the drywall in my living room. Today I found out. It is not what I expected!

I am installing a 2005 Jotul F500. The width of the fireplace is roughly the width of required floor protection for this stove. My plan was originally to remove the drywall and whatever other combustibles were around the brick, make a hearth pad in front of it, and install the stove slightly right of center, to accommodate floor protection clearance for the left side-loading door. I should mention that this room is quite tight so there isn't a ton of play with stove placement.

Here is my problem-
When I did the demo today, I found that the chimney narrows in a way I didn't expect- the flue comes off the left side.

I had planned to run straight up from the stove and 90 into the thimble, and then tee into the new liner. Now it seems that if my plan is to move forward without pretty extreme changes, the pipe would need to jog over a bit. So the question is- is it okay to do a 45 before the 90 into the thimble? My flue will be about 25' tall so I've been presuming a plenty strong draft, but now I'm worried about too many elbows. I suppose this could have been a much shorter post but I wanted to include as much info as possible.

Attaching photos of pre- and post demo.

Thoughts?
(Don't mind the state of the brickwork- dealing with that)

 

[benbirby]

Or, is it possible to attach into the liner at a 45? In which case I could come straight up from the stove a few feet, 45 over, and then two 45s into the thimble instead of two 90s. I've never seen or heard of this, but I figure y'all know everything.

 

[Ashful]

Or, is it possible to attach into the liner at a 45? In which case I could come straight up from the stove a few feet, 45 over, and then two 45s into the thimble instead of two 90s. I've never seen or heard of this, but I figure y'all know everything.

Exactly what I was thinking. More drilling, but you could penetrate that stack at a 45 degree angle, if that's the placement you need to hold.

How are you doing the thimble and liner? Would it be easier to just remove that chimney and build a new chase for the stove?

Some of the brickwork above the lintel of that fireplace looks a bit concerning, but it's hard to tell in that photo.

BTW, 1880's isn't "very old"! This house has an addition that was over 100 years old, by 1880! Be glad your place was built with Portland cement between the bricks.

 

[benbirby]

Exactly what I was thinking. More drilling, but you could penetrate that stack at a 45 degree angle, if that's the placement you need to hold.

How are you doing the thimble and liner? Would it be easier to just remove that chimney and build a new chase for the stove?

Some of the brickwork above the lintel of that fireplace looks a bit concerning, but it's hard to tell in that photo.

BTW, 1880's isn't "very old"! This house has an addition that was over 100 years old, by 1880! Be glad your place was built with Portland cement between the bricks.

Appreciate the response!

Eeeehhhh, there is 25' of chimney going through two more floors and out the roof (small house but tall and skinny) so I don't think removing the chimney is gonna be a thing here. But I'm happy to hear every idea!
I'm gonna get the chimney guy back out to make sure he's good with me repairing the brickwork (also not so sure there's portland in there...).
I'll also ask him about drilling at a 45.

My plan was to do all the interior work (besides cutting the thimble) and let him focus on the exterior, because my roof has a craaazy steep pitch.

I'm mainly trying to figure out whether or not the draft requirements will allow for another 45 in the connector pipe but like I said, happy to hear all thoughts!

 

[Ashful]

I'd wait to see what chimney pro says. Core drilling diagonally is possible, but really affects stability, unless perhaps a clay thimble is mortared in. We usually see thimbles into the smoke shelf area, but yours is so damn low that doesn't seem practical.

I suspect they're going to tell you it's best to only drill the center of a chimney face (for mechanical stability), in which case you could come into the side to resolve the height and centering issues.

Oh, and your chimney is almost definitely built with Portland, given the age. I was referring to older homes, which can have only mud (no lime, no Portland) as their bedding mortar. This can cause walls and chimneys to just crumble apart, if pointing or stucco isn't maintained, as the mud just washes out with rain and weather. Makes projects like this much more interesting and challenging, as everything is moving while you're working.

 

[benbirby]

I'd wait to see what chimney pro says. Core drilling diagonally is possible, but really affects stability, unless perhaps a clay thimble is mortared in. We usually see thimbles into the smoke shelf area, but yours is so damn low that doesn't seem practical.

I suspect they're going to tell you it's best to only drill the center of a chimney face (for mechanical stability), in which case you could come into the side to resolve the height and centering issues.

Oh, and your chimney is almost definitely built with Portland, given the age. I was referring to older homes, which can have only mud (no lime, no Portland) as their bedding mortar. This can cause walls and chimneys to just crumble apart, if pointing or stucco isn't maintained, as the mud just washes out with rain and weather. Makes projects like this much more interesting and challenging, as everything is moving while you're working.

What do you mean when you say "come into the side"?

Do you mean the right side of the chimney rather than the face? So up from the stove, 45 back towards the exterior wall, and then thimble to the left?

I just found out my chimney guy is out of the country until 10/1 so I'll be over here scratching my head for a minute.

 

[benbirby]

Side question-
I had originally planned to continue the tile I'm laying for the hearth up the first few feet of the brick and just clean up the rest, but given this shape and the fact that this brickwork was built to never be seen, I don't think I'll be doing that. My next best idea is to use some sort of stucco to render the whole thing a little more flat and even, and resolve the weird brick and cement fireplace plug.
Any reason that would be a bad idea?

 

[EbS-P]

I’m trying think of the most simple solution. F500 can rear vent. Can you come straight down then angle the terminating T at 45 degrees and then have enough room for another 45 at the back of the stove? Stove ends up centered in the opening and no holes new holes needed.

 

[pyrotom]

Howdy folks,

I need some advice.

**TL; DR -- can I do a 45 to jog over connector pipe before going into thimble?**

Apologies in advance if this is a ramble, will try to include all relevant information.

I am doing a new stove install in a very old house (1880s).
I recently got a new boiler and water heater so my chimney is now vacant. I have a chimney company coming in a few weeks to do some repair above the roofline, install a new liner, cut a hole for the thimble and hook up the stove.

In the meantime......
In the 10 years since I've owned the house I've always wondered what the old fireplace looked like behind the drywall in my living room. Today I found out. It is not what I expected!

I am installing a 2005 Jotul F500. The width of the fireplace is roughly the width of required floor protection for this stove. My plan was originally to remove the drywall and whatever other combustibles were around the brick, make a hearth pad in front of it, and install the stove slightly right of center, to accommodate floor protection clearance for the left side-loading door. I should mention that this room is quite tight so there isn't a ton of play with stove placement.

Here is my problem-
When I did the demo today, I found that the chimney narrows in a way I didn't expect- the flue comes off the left side.

I had planned to run straight up from the stove and 90 into the thimble, and then tee into the new liner. Now it seems that if my plan is to move forward without pretty extreme changes, the pipe would need to jog over a bit. So the question is- is it okay to do a 45 before the 90 into the thimble? My flue will be about 25' tall so I've been presuming a plenty strong draft, but now I'm worried about too many elbows. I suppose this could have been a much shorter post but I wanted to include as much info as possible.

Attaching photos of pre- and post demo.

Thoughts?
(Don't mind the state of the brickwork- dealing with that)

View attachment 315798 View attachment 315799

Yes, it's OK to jog 45 over and 90 into a thimble and go into a tee and liner. The amount of smoke in the chimney will create a siphon effect and should overcome the initial elbows. Once I put my kindling and wood in a stove, I place some fast-burning paper on top of the pile and light it first to pre-heat the flue. You can also use a draw collar to heat the flue if you still have trouble: https://theatmosfire.com/products/draw-collar-for-wood-burning-stoves

 

[benbirby]

I’m trying think of the most simple solution. F500 can rear vent. Can you come straight down then angle the terminating T at 45 degrees and then have enough room for another 45 at the back of the stove? Stove ends up centered in the opening and no holes new holes needed.

I'm trying to picture exactly what you mean. This would exit the chimney in the wider firebox area?

In considering this, is it possible to flex the liner over to the right inside the firebox area and then tee straight into the stove as a rear-vent?

 

[benbirby]

Yes, it's OK to jog 45 over and 90 into a thimble and go into a tee and liner. The amount of smoke in the chimney will create a siphon effect and should overcome the initial elbows. Once I put my kindling and wood in a stove, I place some fast-burning paper on top of the pile and light it first to pre-heat the flue. You can also use a draw collar to heat the flue if you still have trouble: https://theatmosfire.com/products/draw-collar-for-wood-burning-stoves

Okay great.
I'm ready to hear every possible solution people have for the most ideal setup here, but I'm glad to know that at least this is an okay thing to do .

 

[Ashful]

What do you mean when you say "come into the side"?

Do you mean the right side of the chimney rather than the face? So up from the stove, 45 back towards the exterior wall, and then thimble to the left?

I mean, come off top of stove, straight up, then angle back 45 to a 90 inserted into thimble on side of chimney:



If you really need to get the thing centered in front of the fireplace, this might be the closest option.

Then again, if you're covering over fireplace with drywall or other, how critical is it that you get the thing so well centered?

 

[benbirby]

I mean, come off top of stove, straight up, then angle back 45 to a 90 inserted into thimble on side of chimney:

View attachment 315821

If you really need to get the thing centered in front of the fireplace, this might be the closest option.

Then again, if you're covering over fireplace with drywall or other, how critical is it that you get the thing so well centered?

Well, planning NOT to cover with drywall or any other combustibles to keep clearances at a minimum.


Maybe I wasn't totally clear in my first post. The issue is that rather than centering the stove, it needs to actually be cheated to the right a bit, so that it has the appropriate floor protection for the left side loading door. So the pipe will come up even a little right of center. Can't really push the stove further to the left because there's also a pass-through to the next room over there that I can't block.

 

[benbirby]

I do aesthetically like your idea of tapping into the side rather than front of the chimney for several reasons.

 

[EbS-P]

I'm trying to picture exactly what you mean. This would exit the chimney in the wider firebox area?

In considering this, is it possible to flex the liner over to the right inside the firebox area and then tee straight into the stove as a rear-vent?

How high is the fireplace opening? How far off center of the opening for you want the stove?

You have some flex. Think 18” -24” bend radius. I’m not sure on how to connect the T to the angled adapter on the stove. More flex liner? Or does it have to be stove pipe? You can get 15, 30, and 45 degree appliances adapters.

As long as you don’t have short legs all you need is ember protection. That could just be a thin sheet metal or tiles with grout on the floor.

 

[begreen]

The rear vent option with a slight rise of the connector into the liner tee looks like the most straightforward and inexpensive approach. The liner may be able to curve at the bottom to provide the offset angle with the attached tee at the bottom.

What is the chimney condition, especially outside where it's exposed to the elements? Will there be the expense of repointing or a new crown? Is it clay-lined or raw brick? What is the ID?
If it's in dubious condition, I like Ashful's idea of just removing the fireplace and chimney, and then replacing it with a class A chimney system. It's not as hard as it sounds, especially with old brick. My son and I removed ours (2 story) in 2 days.

 

[benbirby]

I thought it might be helpful if I made a visual demonstration of what I'm looking at. I taped out the size of the hearth pad, the horizontal and vertical position of the stove on the floor and wall, and where the pipe would come up. I thought that might be more helpful than hitting y'all with a bunch of numbers but numbers can be had!
(Hearth pad size and position of stove based on the spec sheet from Jotul)

 

[benbirby]

The rear vent option with a slight rise of the connector into the liner tee looks like the most straightforward and inexpensive approach. The liner may be able to curve at the bottom to provide the offset angle with the attached tee at the bottom.

What is the chimney condition, especially outside where it's exposed to the elements? Will there be the expense of repointing or a new crown? Is it clay-lined or raw brick? What is the ID?
If it's in dubious condition, I like Ashful's idea of just removing the fireplace and chimney, and then replacing it with a class A chimney system. It's not as hard as it sounds, especially with old brick. My son and I removed ours (2 story) in 2 days.

The chimney above the roofline is getting repointed by the chimney pro. I'm not sure about the lining.

I'm not dogmatically opposed to getting rid of the chimney necessarily, but it goes through two more floors of my house before the roof. On the second floor it's enclosed in drywall in a bedroom. In the attic it's not enclosed but it's painted and goes through a finished room. My roof is also a very extreme pitch, too steep to walk on, and the side of the house that the chimney is on is an alley, so scaffolding isn't an option. The chimney guy is going to use a boom lift to do the above-roof work.

Not trying to make excuses or to keep the chimney out of sentiment, but I think it truly is the most reasonable option.

 

[benbirby]

How high is the fireplace opening? How far off center of the opening for you want the stove?

You have some flex. Think 18” -24” bend radius. I’m not sure on how to connect the T to the angled adapter on the stove. More flex liner? Or does it have to be stove pipe? You can get 15, 30, and 45 degree appliances adapters.

As long as you don’t have short legs all you need is ember protection. That could just be a thin sheet metal or tiles with grout on the floor.

View attachment 315822

Thanks for the drawing. This is helpful.

This is starting to seem more doable to me. Obviously I will be letting the chimney guy weigh in but I just wanted to have a couple ideas up my sleeve first (and to know it is going to be in some way possible).

I have the normal height legs. The stove didn't come with the bottom heat shield but I'm going to get one. I do have the rear heat shield.
My plan is to cut out the floor and make a tiled hearth pad that is flush with the rest of the floor (hardwood). The size of pad needed is so big in relation to the size of the room that any amount of rise would be a real nightmare. This is the one element of the project that I feel I have a handle on 😅

 

[begreen]

 

[benbirby]

Howdy folks,
I'm back because the stove is going in tomorrow! Will post pics of the whole project once it's done.
I'm here with a question-
The chimney guy (who I have found to be honest and knowledgeable) insists that double wall connector pipe from the stove to the thimble is unnecessary. Should I insist on this? And what is the reasoning?

 

[begreen]

As long as there are no combustible (now or in the future) within 18', in that short run it's not a necessity. It is important that the stovepipe be sloped upward toward the liner tee at least 1/4" / ft or more.

 

[benbirby]

Thanks! It will not be within 18" of combustibles.

 

[Ashful]

Single wall increases heat loss from connector pipe, which can be a problem on some stoves with extremely low burn rates (eg. Blaze King, Woodstock), where there's very low heat going into the pipe, allowing gasses to condense before the reach the top of the flue. This should not be a big problem on a Jotul, in most cases.

 

[benbirby]

Well here's hoping it's not an issue. If I need to replace it down the line I can do that.

Here's a progress picture (obviously still some finishing work left to do)... but it's come a long way and I'm glad to have the stove no longer a sad paperweight in the room....
Unfortunately it's still so warm here that I haven't even thought about turning on the boiler...
Might do a test fire tomorrow just for the hell of it



The shape is a bit oddball, but that is pretty much the way things go in my house...
For the record, I asked chimney guy today what the total length of liner was and he said it's 26' (above the thimble). So I think I should be okay on draft, even with that added 30° elbow.