Duct hits a rated wall at a 45-degree angle and the fire damper cannot sit square

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.

Stop if

• The duct approaches the rated wall at a 45 and the damper will not sit square in the sleeve. I stopped before cutting/setting it. Do you want an upstream offset to square the duct to the wall or a detailer RFI?

Watch out

• Do not install a fire/smoke damper cocked at an angle through a rated wall because the duct line came in crooked.

Check

• Confirm the wall rating and damper type.
• Check manufacturer installation instructions for allowed orientation.
• Verify sleeve is square to the wall plane.
• Lay out upstream elbows/offsets to enter perpendicular if required.
• Do not cover until access, sleeve, angles, and firestop are accepted.

Steps

• Confirm the wall rating and damper type.
• Check manufacturer installation instructions for allowed orientation.
• Verify sleeve is square to the wall plane.
• Lay out upstream elbows/offsets to enter perpendicular if required.
• Do not cover until access, sleeve, angles, and firestop are accepted.

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