I am finishing my basement and have 2 runs to add today so I can frame in my soffit. The runs that are already installed that go to the first floor tap into the main trunk from the top. Is it acceptable to tap in from the side if enough space is available? My soffit extends over the HVAC, water, and gas lines. Any tricks to cutting out a 6" hole? I was planning to use the small 6" connector with the tabs, followed by a 90 degree followed by another 90, then several sections of 5'.
Once I get these runs installed today, the ends will be wide open, and I will not have anything to close off the air flow until my drywall gets installed. Can I cover this with anything until I get to that stage? Typically, the vents already installed off of the main trunk are always closed. I also plan to remove these and cap off. Do I need to use the self tapping metal screws, or is the HVAC caulking sufficient? I noticed there were no screws on top, just tape.