I have a house with a truss attic and 12/9 pitch. It has loose full insulation and soffit vents every other 24” section. There are cardboard baffles that are 33” long. They have print on them that says this “side up, treated side”. Whoever installed them put that side “down” instead. So the treated side touches the insulation and most of them are bowing. I’m considering replacing them and re-doing the install. What kind of baffles do folks in the biz use for the best insulation performance? The other issue is that I have a shake roof and in some of the bays the tar paper comes down through the slats a bit and blocks the airflow, so it would be nice to have a baffle with some ribs. In a few years I’ll be replacing the roof but I want to get the soffits into the best shape insulation wise..
Also, should every single soffit cavity have a baffle regardless of if it has vent openings?
I would be better to have every bay vented, as long as there is a space for air to travel I wouldn't be to worried about the card board ones, And if you can read them this side down, are you not on the down side while reading it.
Your shake roof is likely on strapping and the bottom few feet may be solid but you will have cross venting where you have open spaces between the strapping.
Do not use flat bottom gables with scissor trusses.