Chimney Questions

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I'm a little confused about when to use single, double wall, and Class A. Below I have a diagram of my situation with numbers on the chimney. I have two questions.

1: Do I need class A after for parts 1, 2, & 3? The only thing they are next to is brick, which I'm assuming is non-combustible.

2: What do I use to surround the horizontal pipe going through the window? (see blue)

Thank you so much

 

[tiber]

Is there a question here? Just from the illustration - Not allowed.You have to brick up the window to make it stop being a window.

 

[begreen]

Pipe 6 can be single or double-wall connector pipe, depending on the clearance requirements and length of the pipe run. Pipe 4 will depend. Is this a new installation going through a brick wall? If so, this thimble will be class A pipe. Pipe 2& tee 3 will also be class A.

 

[tiber]

I see you edited the question after I replied.

1, 2, 3 and 4 will be class A (along with the T). The problem of going through a window (5) still stands - you're not allowed to do it unless you rip out the trim, etc and brick it up.

Part 4 is actually the thimble, but inside of it is class A. The class A has to come two inches into the room at minimum. There's an adapter which goes between pipe 6 (stovepipe of single or double wall construction) and part 4 (class A going into the thimble). Sometimes this also includes a trim piece.

 

[[email protected]]

1. Pipe will go through where now exists a window. Yes, I realize I will have to brick-up the window. However, this is an old (1890's) building and I would not like to damage the existing wooden trim and window. My thought was to building a removable "block of bricks" designed for the pipe to exactly fit.

2. Why does the exterior (sections 1, 2, and 3) have to be Class A? The exterior of the building is entirely brick and ceramic. There will be NOTHING combustible within a yard or two of the pipe.

 

[Renovation]

2. Why does the exterior (sections 1, 2, and 3) have to be Class A? The exterior of the building is entirely brick and ceramic. There will be NOTHING combustible within a yard or two of the pipe.

Just shooting from the hip, what if some trash or paper blew up against the pipe? A branch fell against it? Someone leaned something against your house? Someone fell against it? I'm imagining the reaction from your insurance company. :bug:

 

[[email protected]]

Gotcha on that. It's just hard to accept $1200ish for pipe. I'll just have to bite the bullet.

 

[begreen]

Why class A? Besides safety, better draft and less creosote with an insulated flue.

Unless I am misunderstanding code, I don't think you need to brick up the window. What you do need to be sure of is that the horiz. thimble honors clearances. As far as the window goes, with a wall thimble assembly I don't see why you couldn't cover the window opening with plywood, on both sides, then install the wall thimble assembly through it. Am I missing something here?

 

[Renovation]

Gotcha on that. It's just hard to accept $1200ish for pipe. I'll just have to bite the bullet.

As someone who can be very stubborn, I hear you and salute your acceptance. Sometimes biting the bullet is better than grinding your teeth off.

The upside is it seems to me that BeGreen has an easy solution for you--the chimney can't tell if there is a window frame outside of its thimble, as long as it's secure. And you'll be enjoying your fires long after they've paid for the chimney, and the cost is forgotten.

 

[[email protected]]

After pricing everything and taking a second look at the project, it's about $400 cheaper to go through the ceiling. And maybe a little less work. So, I think I'm going to do that.

 

[Renovation]

After pricing everything and taking a second look at the project, it's about $400 cheaper to go through the ceiling. And maybe a little less work. So, I think I'm going to do that.

Designing is fun, ain't it? And doesn't cost more than our time. What's that worth? ;-)

In another thread, I'm leaning towards taking the advice I gave you, and springing for the better chimney (in my case, 8" versus 6"). I'm also amusing myself by looking at an option you might consider--using a ceiling mount, but installing it in an insulated external chase, which is then part of the house's heated envelope. This would give a straight chimney. the advantages of an interior chimney, and a cheaper ceiling mount. while moving the stove back out of the room a bit and avoiding having the chimney run inside through my second floor. Sort of a half alcove, with the rear of the stove slightly behind the original rear wall. The downside is having to build the exterior chase, but I'm going to see if I can control costs by not running it all the way to the ground, so that I don't have to extend my foundation.

I'm going to look into clearances, fireproof material options, etc., and see how it plays out.

Comments and advice anyone?

Happy designing!

 

[[email protected]]

What you are planning seems to be what every diagram shows.