A framing crew is installing I-joists for a floor system. The plans call for a 200 mm diameter duct to pass through the web of an I-joist. The I-joist manufacturer's specifications allow for a maximum 150 mm diameter hole in this particular joist depth, located in the middle third of the span and away from flanges. What is the best course of action for the crew?

Question: A framing crew is installing I-joists for a floor system. The plans call for a 200 mm diameter duct to pass through the web of an I-joist. The I-joist manufacturer's specifications allow for a maximum 150 mm diameter hole in this particular joist depth, located in the middle third of the span and away from flanges. What is the best course of action for the crew?

Answer options:

• Cut the 200 mm hole as planned, as the duct is rigid and will provide support.
• Cut the 150 mm hole and try to force the 200 mm duct through it. ✅ Contact the structural engineer or designer to find an alternative solution or request an engineered reinforcement detail.
• Cut the 200 mm hole but reinforce it with plywood on both sides of the joist web.

Correct answer: Contact the structural engineer or designer to find an alternative solution or request an engineered reinforcement detail.

Explanation: Exceeding the manufacturer's specified hole size or location for I-joists can severely compromise their structural integrity. The only safe and correct course of action is to contact the structural engineer or designer. They can provide an engineered solution, such as re-routing the duct, using a hanger, or specifying a reinforcement method, to ensure the floor system remains structurally sound.