ᐅ Insulating a vertical roof vent through the roof in a cold roof assembly?

Hello dear forum members,

Our plumbing vent pipe passes through the vapor barrier and the insulation between the rafters into the cold roof space, and then goes outside through the roof.
Does the pipe need to be additionally insulated in the cold roof space, or is that not necessary?

Thank you very much!

No! If any condensation occurs, it happens inside the pipe, and the condensate is safely contained there.

jokersmile schrieb:

No! If condensation occurs, it happens inside the pipe, and the condensate is safely contained there.

Thank you for your response.
Would it make a difference if the pipe were insulated?

No, that doesn’t matter.

Condensation can also form outside the pipe.

It is important that the pipe does not form U-shaped bends. Condensate must be able to drain properly.

In our case, before insulation, the cold roof looked like this. A vapor barrier was installed on the concrete, followed by the insulation. While reviewing the photos, I just realized I need to check whether they placed the wood fiberboard, which they used here as a spacer for the slope, above or below the vapor barrier. Otherwise, this board might absorb moisture and start to rot.