Double wall stovepipe cleareance to wood ceiling

[nshif]

Well my stove ( 4300 Quad ) is in and I should be installing this weekend, if all the stove pipe gets here. My question is how close can the double wall stove pipe get to the knotty pine ceiling ( which is a 6:12 pitch, Susposably my support box is adjustable. All is Simpson Dura Vent . My guess is 6" but just not sure.

 

[BrotherBart]

The manual with clearance info for Dura Vent DuraTech pipe is here:

http://www.duravent.com/docs/instruct/L150 Dec05.pdf

 

[jtp10181]

Actually the 4300 manual over rides that.

Page 11

http://content.hearthnhome.com/downloads/installManuals/man_4300_acc.pdf

This is for the new ACC stoves. It depends on the type of pipe and also if you have a Step Top or a Flat Top.

I pushed Quad on this issue, with the clearances in the manual so much larger than the DVL clearances. The DVL itself is just tested with a constant heat source that just heats the pipe. When they test for the manual they test the pipe on the unit and the addition heat the unit puts off adds to clearance requirements. Basically they said the manual over rides the pipe mfg instructions for clearances.

 

[nshif]

JTP
that page only seems to do with wall CTC. Is it the same for ceilings? Further on in the quad manual they deal with stovepipe connections but I dont really see a ceiling CTC

 

[jtp10181]

See attached pic, its from page 11. Use the table to find your clearances. The second section on the table has "N/A" for "H" because its for 90 right off the top ONLY. Unless you have 4ft ceilings, or the unit on a 4ft platform I don't think you have to worry about that particular clearance with that install. I assume you are doing vertical first then a 90 elbow, in which case you use the first section of the table.

 

[BrotherBart]

See attached pic, its from page 11. Use the table to find your clearances. The second section on the table has "N/A" for "H" because its for 90 right off the top ONLY. Unless you have 4ft ceilings, or the unit on a 4ft platform I don't think you have to worry about that particular clearance with that install. I assume you are doing vertical first then a 90 elbow, in which case you use the first section of the table.

When he said "support box" that indicated a straight up pipe to me.

 

[nshif]

It is straight up pipe close to 16' no horiizontal. Im asking how close the double wall can get to the wood ceiling. I do now realize that the wood will stop about 6" horizontilally from the stove pipe.

 

[jtp10181]

Whops... I missed that little thing about the support box. Since you asked ceiling clearance I was thinking horizontal pipe. Gonna have to look into this now, never really thought about it I guess.

----

http://www.duravent.com/docs/instruct/L114.pdf

Page 3, First picture on the left. Support box just needs to hang down 2"

They don't really talk about cathedral ceilings in there. I would try to keep the 6" wall clearance from the sides to the ceiling if possible. With a 6/12 pitch if you come down with the support box 3" on the low side, your pipe should be 6" away from the ceiling measuring horizontally... if I did my math correctly.

 

[nshif]

Ok JTP I saw that but wasnt sure based on the double wall CTC but now that I look at the horizontal it makes more sense Thanks

 

[Hogwildz]

If hes going through the ceiling, doesn't he need class A pipe?

 

[Gooserider]

If hes going through the ceiling, doesn't he need class A pipe?

He needs Class A from the support box UP, but can go with double wall from the stove to the support box.

Gooserider

 

[pcampbell]

Guys,

This question has perplexed me. Obviously I want to be exactly careful.

I am going to be using the Simpson Duravent DVL (double pipe).

I understand that the support box needs to only hang down 2" as per Duravent, but the Duravent DVL manual says that the black DVL pipe must be 8" from the ceiling.

If the support box is only 2" below the ceiling, wouldn't that make the DVL pipe 2", not 8" from the ceiling???

I must be reading too much into this. Common sense tells me if you use a support box, and support box says you must be 2" below the ceiling, and furthermore that Simpson says the Class A pipe should end at the support box, then you can hook the black DVL directly up to the bottom of the support box and all is OK, but the manual seems slightly contradicting on this. Simpson specifically states the class A should end at the support box...

 

[tutu_sue]

Just to make things more confusing Duratech Class A manual it says 3" below the finished ceiling for round support box. While the DVL manual says 2", but doesn't specify round or not. I understand that a horizontal run of DVL needs to be minimum 8" from the ceiling, but if your stove manual says more, you need more.

pcampbell, running straight down from the ceiling and not having an elbow with a horizontal run of DVL, than the 8" ceiling clearance doesn't apply to your installation.

I'm going to contact Simpson to see if the round ceiling support box I'm going to use needs to hang down 2" or 3" from the ceiling. Oye! God is in the details (and so are insurance companies, right?)

 

[pcampbell]

Cool thanks. That is what I thought. I had 2 questions for Simpson this morning and they answered me immediately.

 

[Metal]

It says "2" minimum" you need to make it hang down far enough to get the necessary clearance to combustibles. For example, the support box extends out 3" around the pipe, so if you need 6" CTC then you just calculate using the Pythagorean Theorem. So you need to extend the box down ~5.2" to get 6" CTC (if that is what the stove manufacturer requires).

Calculation:
3 squared + 5.2 squared = 6 squared, with 3 being the distance from the outside of the double wall pipe to the edge of the ceiling support, 5.2 being the length of box in the room on the short side, and 6 being the required CTC.