Cubic Mini Grizzly and finding stove pipe

[ccgro]

Hi
I have a new Cubic Mini Grizzly with a 3" flue . BHoller if you are here who is tgey? Will they fabricate and sell to genl public. Olympic won't

I want a custom class A double wall pipe going from stove through rooftop if possible. I am going through an aluminum roof that already has a 6x12 vent with a hood 6" above roofline i will drill through to get outside . The vent was for the propane fridge where it once sat.

I will have minimal clearance from flue to wall so cement board will cover wall. Cubic mini sells wall mount that has 2" clearance to combustibles but i want something more substantial so i am building walls and will cover with tile metal or such.

I hope i added this pic correctly

Camper

• ccgro
• Dec 28, 2018

Enlarge and you will see the vent hole in the ceiling. Right above that is the metal box and...

 

[begreen]

This site has parts for a 3" chimney system
https://www.tinywoodstove.com/product-category/3in-flue-parts/

The shielding system sold by Cubic for the Grizzly should be ok. It provides the required air gap and it is tested.

 

[begreen]

Please let us know what you find out. It's probably the closest to class A that you will find in 3". Class A chimney pipe is available at 5" which would work fine for this application. It would need a 3" to 5" increaser.

Cubic makes a wall shielding for the single wall flue pipe. Or a shield could also be attached on spacers to the flue pipe.

 

[ccgro]

Thanks begreen, I have been looking at that site this week. Appears their set up is single wall to double wall. Can't do any single wall or if i do it has to be very minimal at stove exit. IF all else fails and i can't find a custom shop that sells to public they will be my choice
. I have not seen any other double wall that has ceramic insulation. why insulated?

 

[begreen]

Can you explain the need for double-wall stove pipe? What problem are you trying to solve?

The tiny woodstove site's ceramic insulation stainless pipe is the only one I have seen in 3".

 

[SpaceBus]

Keep us updated on this project. I lived in a 38' class a for two years with my wife and our dogs. We gutted it and almost finished renovating it.

 

[ccgro]

Good point . I will have to try running a pvc pipe from my stove to my vent to mimic the o.d. diameter of the 5 inch pipe, May be too tight of a squeeze and too close to wall. Another question ...I am using 1/4 cement board on wall . should i use a secondary barrier with an air gap such as stainless or galanized on top of board? Will cement board and possibly tile be enough? I have 2 inch foam board insulation in wall,

 

[begreen]

If this is a mobile home then there are additional issues besides firmly anchoring the stove. One is chimney height. That is, how much projection out of the roof before it becomes a hazard or nuisance? In this circumstance the complete Dickinson package, Newport stove, flue and flashing may be an alternative? Or if the budget can handle it, there is the Kimberly stove. They also sell venting accessories in 3", but I know nothing about what they are selling.
https://www.unforgettablefirellc.com/custom-venting-kits/

 

[ccgro]

begreen.
From all i read the single wall pipe will not allow the gases to be hot enough to minimize cresote. The cubic mini site now recommends double wall as well as problems of cresote arose when using single wall. The chimney will be removed for traveling and replaced by a cap.

 

[begreen]

Good point . I will have to try running a pvc pipe from my stove to my vent to mimic the o.d. diameter of the 5 inch pipe, May be too tight of a squeeze and too close to wall. Another question ...I am using 1/4 cement board on wall . should i use a secondary barrier with an air gap such as stainless or galanized on top of board? Will cement board and possibly tile be enough? I have 2 inch foam board insulation in wall,

1/4" cement board is going to be fragile. It will do no more than a sheet of metal as far as wall protection goes. That is why I suggested going with the manufacturer's heat shielding system that they have tested with.

 

[begreen]

begreen.
From all i read the single wall pipe will not allow the gases to be hot enough to minimize cresote. The cubic mini site now recommends double wall as well as problems of cresote arose when using single wall.

My guess is that the creosote issue is from smoldering fires and burning poorly seasoned wood. Dry wood and a proper fire will keep flue gases hot enough (above 250F) to not produce creosote.

Here is the issue: A wood stove can be overkill in a well insulated small space so people tend to turn them down to the point where they smolder. In this case an insulated flue is only going to help a little. It is treating the symptom instead of the problem.

If this is the worry then maybe take the 3" insulated chimney pipe down all the way to the stove, but that may not protect from creosote buildup due to the above mentioned issues.

 

[ccgro]

thank you begreen....

 

[mellow]

Maybe I am missing something but can't you use DuraVent PelletVent 3 in. x 6 in. Double-Wall Chimney Stove Pipe found at Home Depot?

 

[begreen]

Maybe I am missing something but can't you use DuraVent PelletVent 3 in. x 6 in. Double-Wall Chimney Stove Pipe found at Home Depot?

It's a low temp vent pipe, not made for this application so one would be using it off label. The continuous temp rating is lower than wood stove pipe. Then there is the problem of connecting it to the stove and chimney.