Is it normal for these baffles to feel this tight against the rigid foam?

The critical part of that rafter setup is maintaining at least a **two-inch air gap** between the top of your insulation and the underside of the roof sheathing. If those pink boards are pressed right up against the plywood or OSB, you've essentially killed your ventilation. Even if you've left a small gap, the spray foam around the edges can create little pockets where moisture gets trapped. That moisture migrates from the warm side of the house, hits the cold roof deck, and turns into liquid water. Over time, that is how you get mold and wood rot. You need to ensure that the air coming in from the soffits has a clear, unobstructed path all the way to the ridge vent. If you're using foam board between the rafters, I usually recomend using **plastic baffles** first, then installing the foam board over them. That way you have a guaranteed physical channel for the air. If you've allready foamed them in tight, you might need to back those boards out a bit. It’s a massive pain to redo, but it beats replacing a roof deck in five years beacuse it rotted from the inside out.

As for the floor section, sealing the white foam board is good, but make sure you’ve addressed the **joist bays** directly under the knee wall itself. Most people forget to block those off. If those bays are open, the heat just bypasses your floor foam and sucks right into the attic space. You want to create a continuous air barrier that follows the envelope of the room. Use blocking—either wood or rigid foam—and seal it with more of that canned foam to stop the chimney effect from pulling air out of the rooms below.

Don't worry too much about over-engineering the seal itself; you want it airtight on the warm side. The problem only starts when you stop the cold side from breathing. If you've got that airflow moving behind the foam, you're in good shape. Just double-check that you can acutally feel air movement or see daylight thru those channels before you nail down that plywood subfloor.

Wait, you mentioned blocking the joist bays under the wall—is that the space between the floor boards? I'm a bit lost on where that goes or what it's supposed to look like. Also, how do you acutally 'feel' for air movement if it's such a tight space? I’m worried I’ll seal it all up and realize too late it's not breathing. Should I be able to see the light from the soffits even after the pink boards are in? This stuff is way more complicated than I thougt it'd be when I started.

I've been fixing these 'tight' jobs since before some of you were born. For those joist bays, we used to just cut scrap plywood blocks and nail 'em in solid. None of this fancy foam—just wood and some heavy caulk. If you're wondering about the air, grab a stick of incense or a thin piece of toilet paper. Hold it up to the gap; if it doesn't move, you've got a dead zone. I always tell guys to take a long yardstick and slide it up the baffle. If it hits foam instead of the soffit vent, you're asking for a rotted roof. Keep it simple.

Regarding those pink extruded polystyrene boards, one must be cognizant of the fact that while you are striving for an airtight seal at the perimeter, the timber rafters themselves represent a significant thermal bridge that effectively bypasses your insulation, potentially leading to localized condensation on the interior rafter face if the dew point is reached within the wood. I’d also check for wind-washing at the junction where the vertical knee wall meets the sloped rafter; high-velocity air from the soffit can easily bypass the edges of your floor-level white expanded polystyrene if those transitions aren't mechanically fastened and sealed with a high-tack flashing tape rather than just relying on the canned foam's adhesive properties.

Exactly right about the rafters acting as bridges. I’ve seen frost lines form right along the wood beacuse people forget how much heat those 2x6s or 2x8s actualy move. If you have any of that pink board left over, rip some 2-inch strips and staple them right over the face of the rafters before you finish the wall. It’s a tiny extra step that stops those cold spots from showing trough your finish work later. Just make sure your screws are long enought to bite through that extra layer into the wood!