A crew is framing a floor system for a commercial building. The structural engineer has spec'd a specific type of I-joist (TJ-1800) for a 6.1 m span. During installation, the carpenters discover that the only joists available on site are TJ-1200, which have a lesser depth and span rating. What is the most appropriate action to take?

Question: A crew is framing a floor system for a commercial building. The structural engineer has spec'd a specific type of I-joist (TJ-1800) for a 6.1 m span. During installation, the carpenters discover that the only joists available on site are TJ-1200, which have a lesser depth and span rating. What is the most appropriate action to take?

Answer options:

• Install the TJ-1200 joists at a closer spacing to compensate for the reduced depth. ✅ Contact the structural engineer immediately to report the discrepancy and discuss alternatives.
• Use additional blocking and bridging with the TJ-1200 joists to increase their strength.
• Proceed with installation of the TJ-1200 joists, anticipating later reinforcement if needed.

Correct answer: Contact the structural engineer immediately to report the discrepancy and discuss alternatives.

Explanation: Substituting a structural member with one of a lower specification without engineering approval can lead to serious structural issues and code violations. The most appropriate action is to immediately inform the structural engineer so they can provide a revised design or approve a suitable alternative.