sister joining rafters
If one would click on a picture, 10 total will show the big picture. You only needed (nails) fastening the two rafters side-by-side, per code, not bolts or screws as they bear on a wall there (though you do need solid blocking to prevent rotation). So long as you are not thinking about removing same wall... Remember to cut ventilation notches (or screened holes) in the blocking if using passive roof ventilation. Don't forget the rafter up-lift prevention hardware, and your location would help.
P.S. Welcome to the forums!
Clothes taking longer to dry?
Clean the dryer screen in HOT water if using fabric softener sheets.
They leave a residue that impedes air-flow, costing you money.
Clean the ducting in the last six months? 17,000 dryer fires annually!