Class A pipe temp

[BakerB]

How hot does Metalbestos pipe get ?, and is it ok for it to be touching a little bit of wood going thru roof ?

 

[fespo]

No, I think there should be about 2"-3" away from the pipe

 

[Backwoods Savage]

No! It should not touch the wood. It can get hot enough that you don't want to hold your hand on it.

 

[weezer4117]

How hot does Metalbestos pipe get ?, and is it ok for it to be touching a little bit of wood going thru roof ?

class a stove pipe has a 2" minimum clearence to combustibles. as far as the temp, hard to say. it is designed to handle the heat output of a solid fuel appliance. so its HOT!!

 

[LLigetfa]

Not only should you have the required air gap, I suggest you include a radiation shield anywhere it penetrates a joist or rafter cavity.

 

[SteveKG]

I have three chimneys of Metalbestos. The Metalbestos extends into the living space from the ceiling a bit, so I can easily touch it. After several hours of burning, it is often too hot to touch more than a second or two. You need that insulating airspace, at least an inch or so. The Selkirk spec's call for 2". Over some years, or whatever amount of time, that repeated heating of combustibles at the pipe can lead to combustion. Don't risk it.

 

[Dakotas Dad]

Here you go.. along about page three they cover your question, feel free to read and heed the entire booklet..

http://www.selkirkcorp.com/WorkArea/showcontent.aspx?id=8354

 

[Renovation]

I have three chimneys of Metalbestos. The Metalbestos extends into the living space from the ceiling a bit, so I can easily touch it. After several hours of burning, it is often too hot to touch more than a second or two. You need that insulating airspace, at least an inch or so. The Selkirk spec's call for 2". Over some years, or whatever amount of time, that repeated heating of combustibles at the pipe can lead to combustion. Don't risk it.

Thanks for the data, Steve. To add to it, can you tell us what stove you burn?

Thanks, and happy burning.

 

[SteveKG]

We actually have four. But three chimneys. The main heat stove is an old Shenandoah, been using it for 35 yr. If you are not familiar...they are barrel-shaped stoves lined with firebrick and are large-firebox things. One is a Rais, a kitchen model designed for both heat and baking. Great stove, small oven. That one has been moved out to occasionally heat an attached greenhouse and replaced in the kitchen by a Heartland Artisan, an Aga company, which is a full-service kitchen range cooker [or so they call it]. We've only been operating it a week and a half. The fourth is a small water heater, an "AguaHeater," I bought in the early 80s. It is a dedicated water-heating stove, used only for that so only every couple days for showers and only burns for a half hour or so at a time. The flue for that one is tied in to the flue for the Rais. So they share.

 

[firefighterjake]

Is it OK for plywood to be touching the Class A pipe . . . this would be a resounding NO

 

[Renovation]

We actually have four. But three chimneys. The main heat stove is an old Shenandoah, been using it for 35 yr. If you are not familiar...they are barrel-shaped stoves lined with firebrick and are large-firebox things. One is a Rais, a kitchen model designed for both heat and baking. Great stove, small oven. That one has been moved out to occasionally heat an attached greenhouse and replaced in the kitchen by a Heartland Artisan, an Aga company, which is a full-service kitchen range cooker [or so they call it]. We've only been operating it a week and a half. The fourth is a small water heater, an "AguaHeater," I bought in the early 80s. It is a dedicated water-heating stove, used only for that so only every couple days for showers and only burns for a half hour or so at a time. The flue for that one is tied in to the flue for the Rais. So they share.

Thanks Steve!

Fun to know, and a data-point about Class A flue temps--your relatively warm flue surface temp is with a pre-EPA (I'm assuming) stove, which I'm guessing has relatively warm exhaust gasses--do you have any kind of flue thermometer? Anyway, that's good to know.

Bringing it back to the OP's question, the biggest danger isn't with normal operation, but when something gets out of hand--the stove door is left open, or there is a chimney fire. That's when that 2" clearance could save lives.

Anyone know if there is spec or data on how hot a Class A pipe can get during flue fires? Not that it matters, I'm just curious, as always.

 

[Wood Heat Stoves]

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Anyone know if there is spec or data on how hot a Class A pipe can get during flue fires? Not that it matters, I'm just curious, as always.

rated for 2100* chim fire if it is HT class a

 

[Renovation]

Anyone know if there is spec or data on how hot a Class A pipe can get during flue fires? Not that it matters, I'm just curious, as always.

rated for 2100* chim fire if it is HT class a

Thanks Dave! I'm wondering how hot the outside gets during that condition?

 

[DonNC]

was about to ask a question concerning class a temps during operation, but found this thread. Just installed mine and was curious because of how heavy that pipe is compared to flu pipe. Im thinking I need to put silicone on the chimney seam but didnt see a heat rated silicone on the shelf at Lowes that is also rated for weather. How hot does the outside of your chimney get during operation? If you sealed your chimney, what did you use?

 

[begreen]

I had a seam on some old Metalbestos that I had to silicone. Used a good regular silicone like GE Silicone II and it worked fine. The surface pipe temp under normal operation is way below the limit for regular silicone (400F). If I had to guess it would be about 130-140F in continuous operation. Of course in the case of a chimney fire I could see it getting much hotter. That's the reason for the 2" clearances.

 

[jtp10181]

Wow I missed this original post... now that is yet another scary question.

Can wood be touching a solid fuel flue pipe??? Sure, just plan for this in the near future.
http://alliancechimneyli.com/images/HouseFire_2.jpg

Seriously poeple... how do you install this stuff and not read the instructions.

You are putting a box full of FIRE, in your HOUSE!

 

[yooperdave]

.

Anyone know if there is spec or data on how hot a Class A pipe can get during flue fires? Not that it matters, I'm just curious, as always.

rated for 2100* chim fire if it is HT class a

the 2100f rating is for TEN minutes only!! (the ht pipe is rated for 1000f continuos use.) if chimney fires only lasted 10 minutes, the fire dept wouldn't even be on scene by the time it was over!


MINIMUM 2" CLEARANCE