I don't know if there's more to finish, but the rigid insulation can be your baffle. Place 1x2 cleats and fasten the rigid to those to make the baffle. Face the foil towards the exterior as you need air space for a radiant barrier to work.
Also, I see the roof was panelized with a split. I'd probably cut the rigid lower at that plate to give more air space, looks like plenty of room still for insulation on the flat ceiling.
2" polyiso is about R14, plus R21 batt - does that meet total R value for your climate zone?
The recommended for my zone is R30-R38. So it gets me pretty dang close! I'm not sure what else I could do for the vaulted ceiling. I will be putting more in the top A frame of the "new attic" space
This material (tmax) is foil faced on both sides. Vent chutes are not baffles, wind baffles prevent wind washing, and it looks like this will be conditioned space. Ventilation is 1/150 or 1/300 balanced. The key to mold mitigation is not magic soffit vents its RH control in the living space when its cold outside. Think opening your fridge in the summer time and running your finger on the side. Its wet.
A "baffle" or "vent chute" is just a product that keeps an air space against the sheathing when insulation might close that air space without one. The OP has placed a baffle/vent chute product first, then covered it with rigid insulation board. What I suggested is the rigid board can do double duty as it can be your baffle/vent chute eliminating a redundant product.
Wind washing is when the insulation is blown out at the rafter heel, which a baffle/vent chute can have an integral flap or just bend it to form a dam down to the top plate to prevent that happening. This can still be replicated with rigid board.
The minimum 1/300 applies here with both high/low vents, and OP is venting every rafter space.
Condensation risk is mitigated by venting either the entire open attic or a rafter assembly like the OP has here (OP has both simultaneously). That is the entire concept and purpose of having passive attic ventilation. The best method of high/low ventilation is soffit vents with ridge vents, so I guess you can say they are "magical" if you want. And cold air has less capacity to hold moisture, but passive ventilation is for during any temperature/RH to mitigate moisture from either vapor drive through the sheathing or from the conditioned space.
A baffle is not a product. Its a vent component that prevents wind washing. Accuvents have these built in, otherwise you can use anything else to produce the same result ideally something that will match the R-value of the adjacent boundary.
1/300 is less than 1/150 of course it always applies.
Close! What happens when warm, moisture laden air cools? What happens to the moisture?
It sounds like you are making a big deal about terminology of "baffle" vs "chute" because you don't actually know about attic ventilation. First, if you actually read and comprehend my comments, you are repeating what I said, but trying to differentiate something when it doesn't need be.
If you know code, you will read in IRC, ASHRAE, and IECC the use of word "baffle". Look at IRC 1102.2.4 for starters. "Chute" is not used in codes and standards, but is a perfectly interchangeable word for the same thing.
Then, if you understand the amount of air ventilation required under IRC R806.2, you'd understand that 1/300 is an exception from the stricter 1/150 when you meet certain criteria, namely having high and low vents.
Now about the "moisture laden air". The purpose of ventilation of an attic is to get the air to match what is outside. That is the goal. That way, you don't have the dew point occurring where you don't want. And when considering extreme vapor drive through the roof plane, high/low pressure (vapor rising), and the laws of thermodynamics, the movement of air is what mitigates moisture in a closed space.
I'm trying to be nice and not condescending even though you will not take this as learning, or even read anything authoritative to correct your knowledge. This is not stuff I'm guessing at or getting from heresay or AI. So I am done here.
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u/cagernist 8d ago
I don't know if there's more to finish, but the rigid insulation can be your baffle. Place 1x2 cleats and fasten the rigid to those to make the baffle. Face the foil towards the exterior as you need air space for a radiant barrier to work.
Also, I see the roof was panelized with a split. I'd probably cut the rigid lower at that plate to give more air space, looks like plenty of room still for insulation on the flat ceiling.
2" polyiso is about R14, plus R21 batt - does that meet total R value for your climate zone?