Class A Chimney Pipe install Question - Selkirk Replys

[coverdome]

Can I use rock wool insulation around ( touching) the class a chimney pipe in the required "2 inch clearance " where it goes thru the roof? Sorry if this has been answered 50 times before. Searched but didn't find anything. Hate to leave a big air gap in a really tight house.

Thanks

 

[weezer4117]

Can I use rock wool insulation around ( touching) the class a chimney pipe in the required "2 inch clearance " where it goes thru the roof? Sorry if this has been answered 50 times before. Searched but didn't find anything. Hate to leave a big air gap in a really tight house.

Thanks

Through the roof or the ceiling?

 

[begreen]

The pipe has been tested and certified UL 103HT with the 2" air space.The attic insulation shield is required as well as a firestop below the attic shield if this is a second floor penetration. The firestop should minimize air leakage to the attic. Where is the gap that is of concern? Most attics are already ventilated.

 

[coverdome]

Goin thru the roof in a cathedral ceiling, no attic.

 

[weezer4117]

Goin thru the roof in a cathedral ceiling, no attic.

The flashing around the metal chimney should be sealed almost air tight. The flashing around my chimney has small vents in it with a storm collar covering them. Your roof vents will let more air escape than the flashing, nothing to worry about....

 

[begreen]

Call the manufacturer if this is a concern, but I think there will be minimal leakage. The cathedral support box usually acts as a firestop.

What brand pipe/support box are you installing?

 

[coverdome]

Working with Selkirk Metal Best 8"
Have Roof support brackets and a wall support bracket inside about 4' below the roof.
Bit of overkill, but I have 12" of chimney and about 20' of dbl wall stove pipe.

 

[DanCorcoran]

Working with Selkirk Metal Best 8"
Have Roof support brackets and a wall support bracket inside about 4' below the roof.
Bit of overkill, but I have 12" of chimney and about 20' of dbl wall stove pipe.

Assume you mean 12 feet of chimney, not 12 inches?

 

[begreen]

Working with Selkirk Metal Best 8"
Have Roof support brackets and a wall support bracket inside about 4' below the roof.
Bit of overkill, but I have 12" of chimney and about 20' of dbl wall stove pipe.

Selkirk is pretty explicit in their instructions. I didn't find an exception listed:

WARNING: DO NOT PLACE ANY INSULATING
MATERIALS OR RUN ANY ELECTRICAL WIRING
WITHIN THE REQUIRED AIR CLEARANCE SPACE
SURROUNDING THE CHIMNEY.

 

[coverdome]

That kinda seez it all. Missed that part.

Thanks all.

 

[nate379]

Hmm, the stove place that installed mine wrapped the pipe with rock wood. Metal Best pipe.

 

[coverdome]

Just don't seem right that only thing between the outside air and warm inside air is gonna be the ceiling trim plate.

 

[weezer4117]

Just don't seem right that only thing between the outside air and warm inside air is gonna be the ceiling trim plate.

i know what you mean. Again, you should consider installing a insultaion shield just above the ceiling. This will allow you to insulate closer to your chimney.

 

[BlankBlankBlank]

Coverdome, when I first read your post I was thinking you might be referring to the two inch clearance between the outside surface of your class A pipe and an insulation shield that is used in a ceiling situation. After reading additional posts, I notice that you have a cathedral ceiling support.

Take a look at Selkirk Supervent part number "JUSI". In my literature from Selkirk, this part is listed as "Universal Shielding Insulation" for use with their "Attic Insulation Shield", or "Cathedral Ceiling Support", or "Black Wall Thimble". See the attach photo of the flyer; I circled the part. I'm not sure how the Selkirk SuperVent compares with the Selkirk Metal Best, but I hope this helps you out. You should probably call Selkirk and talk with one of their engineers.

 

[begreen]

+1. I have seen these mineral wool wraps for a competitor's attic insulation guard. But stopped when I came across Selkirk's explicit warning.

Give the mfg a call and let us know what the response is. Better yet, email them and get it in writing.

 

[BlankBlankBlank]

BeGreen, totally agree with getting Selkirk, in this case, to put it in writing. I am confused, though, why would Selkirk produce/sell an insulation for this purpose in their SuperVent line if it's against their install instructions? Unless it's only for their SuperVent line. In this case, Coverdome is using Selkirk's Metal Best line of chimney.

Best to ask the manufacturer.

 

[coverdome]

Selkirk responded to my email inquiry.

Their insulation product SUSI & JUSI is approved for use with MetalBest Ultra Temp chimney.
It is however, only for use inside the Cathedral ceiling hanger, inside the insulation shield, and inside the thru wall thimble.

Apparently they want it enclosed in something. May have to switch gears on the support to use the cathedral box. Hope Dynamite Buys is good with returns.

Thanks to all for the help & info.

 

[BlankBlankBlank]

I'm about to purchase a 6" Selkirk Supervent chimney. I called Selkirk today to find out more about their "Universal Shielding Insulation". According to the technical engineer that I spoke with, they have tested their chimney's with this insulation. It goes between the class A chimney and the heat shield. It is used to fill the 2" air gap to prevent or diminish air flow into the attic or out the roof in a cathedral situation. It is also used in the thimble assembly.

I asked the same question a few times and was assured that this insulation product has been tested and approved to be used with their chimneys. I explained that according to fire code, these 2" clearances are necessary. I was again reassured. So I ordered some. It will arrive by mail to my door within a week.

 

[BlankBlankBlank]

Received the Selkirk SuperVent Universal Shielding Insulation (JUSI) about a week or so ago. Here are some pictures. It looks like fiberglass insulation that has a brownish color. It's probably chemically treated.

 

[woodmiser]

I think Excel uses rock wool between the inside and outside tubes of their class A pipe. The only reason you might not be able to put insulation against the pipe is because they want it to be able to cool in that airspace. By adding an insulation wrap you might cause it to overheat. But since they sell you insulation to wrap it then it seems to me they want to sell you their rock wool, leading you to believe only their stuff is allowed. I'm sure they don't manufacture rock wool... they buy it just like we do. In other words, I think you can use any fire resistant insulation like rock wool or ceramic.

 

[BlankBlankBlank]

I think Excel uses rock wool between the inside and outside tubes of their class A pipe. The only reason you might not be able to put insulation against the pipe is because they want it to be able to cool in that airspace. By adding an insulation wrap you might cause it to overheat. But since they sell you insulation to wrap it then it seems to me they want to sell you their rock wool, leading you to believe only their stuff is allowed. I'm sure they don't manufacture rock wool... they buy it just like we do. In other words, I think you can use any fire resistant insulation like rock wool or ceramic.

Woodmiser, that makes great sense. I was wondering about that myself. Though I also wonder, if one were to use non-Selkirk branded rock wool and a problem arose, would that cause an issue for warranty purposes?

 

[woodmiser]

I think Excel uses rock wool between the inside and outside tubes of their class A pipe. The only reason you might not be able to put insulation against the pipe is because they want it to be able to cool in that airspace. By adding an insulation wrap you might cause it to overheat. But since they sell you insulation to wrap it then it seems to me they want to sell you their rock wool, leading you to believe only their stuff is allowed. I'm sure they don't manufacture rock wool... they buy it just like we do. In other words, I think you can use any fire resistant insulation like rock wool or ceramic.

Woodmiser, that makes great sense. I was wondering about that myself. Though I also wonder, if one were to use non-Selkirk branded rock wool and a problem arose, would that cause an issue for warranty purposes?

You are correct... so now you might be coerced to only use theirs or void the warranty? I guess that could be the case.