| We are going to have a 10" round duct installed from our kitchen vent
| hood and it will exhaust thru the roof. I can't find a roof jack off
| the shelf anywhere that will fit that large a duct, so we might end up
| getting one made. So, I don't know what size to make it, and I think
| it depends on how the duct is attached to the roof jack. The roof
| jacks I've seen are tapered, wider at the bottom than the top. One
| person suggested that the *top* of it (the narrow end) should be 10"
| so you can attach the duct there. Someone else said it should be 10"
| at the bottom and narrow to 8" at the top.
| So, having never attached a duct to a roof jack...how do they normally
| attach, and what size does it need to be? It's a smooth metal duct.
what you want is a "RCVS series vent"
no rubber, no plastic.............just metal.
if your ducting is 8", you need an 8" female end on the bottom of the
roof vent adapter