Apprentice question
Stop and ask
Stop. Get direction before you touch it.
Do not angle a fire/smoke damper through a rated wall unless the listed assembly specifically allows it. Square the duct to the wall with approved fittings before the damper sleeve.
['Fire and smoke dampers are listed assemblies. The sleeve, retaining angles, damper frame, actuator, blade path, and wall opening have to match the installation instructions. A duct hitting the wall at 45° can put the damper out of square and bind the blades.', 'Stop before cutting a slanted rated-wall opening or forcing the sleeve. The likely recovery is to square the duct path before the wall using approved elbows/offsets, or get a detail from the foreman/detailer/engineer.']