Ceiling support boxes

[rdrcr56]

I was reading the Duravent installation instructions for the different ceiling support boxes and was curious why the round support box and the flat support box can be installed with the flat bottom flush with the finished ceiling and the square support box has to be installed with the flat bottom 2" lower than the finished ceiling?

 

[[email protected]]

I looked at the catalogue on-line and it seems that none can be flush with the ceiling.

 

[MountainStoveGuy]

When we talked the other day, i agree that the install guide shows it, i was baffled because the clearance to the double wall is 6 inches. With the three inch protrusion on the round and square support box, it doenst seem like it would be enough. If we dont get a answer here, i will call simpson on wed.

 

[begreen]

I thought that was the reason - the class A pipe connection needs to extend 3 inches into the roomspace before transitioning to single or double wall pipe.

 

[MountainStoveGuy]

Ok, its obvious when you pull both supports out. The flat celing suport box it 14.5 inches square. the 11" catherdral box is 12 inches square. the reason the 12" box needs to be 2 inches further down is because of its size. That how far you need to be to get your 6". On the flat box, wich is bigger, 3 inches down will get you your 6" wich only leaves the collar exposed and no box exposed.

 

[elkimmeg]

I thought that was the reason - the class A pipe connection needs to extend 3 inches into the roomspace before transitioning to single or double wall pipe.

what ever the clearance of the connector pipe is that is the that is the distance the Class A extends out of the ceiling into the room
Remember clearances to combustiables is in all directions 18" for single wall and 6" for double wall connector pipe. If the ceiling boot is not 18" to each side the the Class a has to be extended into the room further

 

[Roospike]

I thought that was the reason - the class A pipe connection needs to extend 3 inches into the roomspace before transitioning to single or double wall pipe.

what ever the clearance of the connector pipe is that is the that is the distance the Class A extends out of the ceiling into the room
Remember clearances to combustiables is in all directions 18" for single wall and 6" for double wall connector pipe. If the ceiling boot is not 18" to each side the the Class a has to be extended into the room further

Sorry buddy .............Again , i couldnt help myself. ;-P