I need to be close to ceiling, but am too close already ..

[pglotov]

Hi All,

I'm installing chimney for my new wood stove (lopi endeavor), and after a day of work am sitting confused and afraid I did it all wrong .. Here is the deal. The pieces I have planned are the following going from the stove to the chimney cap: about 65" of vertical double wall duravent (telescoping), double wall 90 deg elbow (problem spot), horizontal 12" double wall duravent (problem spot), snap on collar, black class A duravent (this piece enters wall thimble and connects to the next piece inside the thimble), 9" galvanized class A, tee, 3 chimney sections up and through the roof .. So today I worked on the thimble installation, found a spot in between studs and horizontal planks, cut some drywall .. The construction of the house is a bit tricky, I had to work from the back of the wall inside of a long 14" wide closet .. In the end of the day the clearance of the combination of elbow & 12" double wall to the ceiling is only 4 ", and the required clearance is 8" .. All other clearances are fine. I am thinking - can I start class A chimney pieces right from the vertical double wall ? This would need a 90 deg class A elbow - will have to check if they make those. Or is there some other way ? Thanks a lot, hoping to get some good advice.

 

[begreen]

Greetings and welcome. Before giving advice that might be off the mark, it would be helpful to see some pictures or simple diagrams of the installation and problem areas. Would that be possible?

 

[pglotov]

Sure, here is a simple sketch. Thanks !

 

[DAKSY]

You should be able to mount a heat shield in the horizontal run to get your specified clearance.
You may be able to mount one on the ceiling to get the same result.
If you have a copy of NFPA 211, the specs are in there for reduced clearances.
I'm sure somebody here has one at hand...
Mine's at work...

 

[daryl]

You can not reduce the clearance of double wall pipe. But you could use a class a tee at the ceiling.

 

[begreen]

That helps, thanks. Where does the 14" wide closet come in? Is it the "wall" indicated in the diagram? This sounds like a false wall. What is it's purpose? Home theater installation?

Seems like the concerns are genuine. Other that having to redo work, are there serious obstacles that would prevent lowering the thimble 4-6" to meet or slightly exceed clearance requirements? I realize this would be a pita, but the job should be done right for peace of mind and legality. If this is being inspected or reported to the insurance co, it's best to follow the book.

 

[pglotov]

That helps, thanks. Where does the 14" wide closet come in? Is it the "wall" indicated in the diagram? This sounds like a false wall. What is it's purpose? Home theater installation?

Seems like the concerns are genuine. Other that having to redo work, are there serious obstacles that would prevent lowering the thimble 4-6" to meet or slightly exceed clearance requirements? I realize this would be a pita, but the job should be done right for peace of mind and legality. If this is being inspected or reported to the insurance co, it's best to follow the book.

The wall is a regular wall, the closet is behind the wall on the picture, it is on the second floor, and the ceiling is a volted ceiling, so on the other side of the wall the thimble enters into the closet right above the floor, and chimney goes up to the roof with tee etc. There is no room to lower the thimble since there are some constructional elements just bellow the current location of the thimble. I'm thinking the suggestion above with class A tee instead of the elbow, and all class A chimney pipes after it will solve the problem, there will be more than 2" required clearance.

 

[pglotov]

You can not reduce the clearance of double wall pipe. But you could use a class a tee at the ceiling.

Good idea ! Thanks, I'll think it over.

 

[pglotov]

45* class a might work better depending on stove location below. cheaper too i thinx

Apparently 45 deg chimney elbows are illegal ..

(broken link removed to http://www.duravent.com/docs/bulletins/2008/45_elbows_product_bulletin.pdf)

 

[pglotov]

45* class a might work better depending on stove location below. cheaper too i thinx

Apparently 45 deg chimney elbows are illegal ..

(broken link removed to http://www.duravent.com/docs/bulletins/2008/45_elbows_product_bulletin.pdf)

consider a 30* ?
theres non logic to this that reveals the simplistic idiocy of code & nfpa211 in general! if u consider the upflow of your fluegas via a 90* turn via tee vs a 45* turn via elbow u might see that 45* elbow provides less fluegas constriction.

Yes, I thought about it, make it like S -shape pipe ...../''''' , the left end will be low enough to connect to 90 deg DW pipe elbow.