Yeah they do actually. I just added a 15x18 addition to my existing living room and was subject to all current PA building codes and the inspector told me they were fine as long as they were panned off, they couldn't be open all the way along the joists inside
Well that's interesting and good to hear all is good with that situation.
I don't really have anything to add except for whatever your decision is I hope it works put great for you.[/quote]
This is going to vary from state to state. Sometimes even from county to county. Some require sleeves with fusible link dampers between floor to act as a firestop. Check with your local inspecting authority.