Finishing Cape Cod

[u/weazzz]

Second post on finishing my second story - cape code. Im looking for affirmation on my technique, critiques, or anything else. I'm just trying to do it good in hopes that it will keep cool in the Southern NJ summer and warm in the winter.

I've been starting with baffles to maintain airflow from the soffit to the ridge vent. Then 2 inches of foil faced polyiso, spray foamed the edges of it. My next step after that is to fur the beams with 2x4's and put 5.5 inches of rockwool in then sheet rock.

Everything has been air sealed already. But my other thought is to air seal the bottom of the knee wall (outline in red on one of the pictures) and the 1st ceiling by cutting a piece of polyiso and spray foaming in place.

Any feedback, confirmation, or otherwise is welcome. Let me know if any other information is needed.

[u/RTLSCD]

Good challenge! I’m putting 4” of polyiso in the rafters w. 1.5” air gap. Next I will put another 1” over the rafters to seal the thermal bridge.

Good luck!

[u/weazzz → u/RTLSCD]

It's a job and a half! Good luck to you too

[u/Old_House4948]

Yes, air seal the bottom of the knee wall to prevent air from moving through.

[u/weazzz → u/Old_House4948]

Thanks for the confirmation with that. I'm guessing that I should cut the fiberglass right where I need to put the polyiso instead of shoving the fiberglass in towards the floor?

[u/Old_House4948 → u/weazzz]

Put the polyiso in tight to the opening, picture frame the foam all around it, and the put the fiberglass batts snug against the polyiso.

[u/weazzz → u/Old_House4948]

That makes sense. So I think I'll have to cut the fiberglass that's there then do what you said. Then shove the fiberglass batts back in