Are My TJI® Joists Causing My Floor to Squeak?

Very unlikely.

TJI® Joists can help you have a quieter floor because they are structurally uniform and dimensionally stable, but only if the entire floor system is installed properly.  Improperly installed hangers, poorly connected partition walls, floor panels that were installed wet, nails that are rubbing against the joist, mechanical systems rubbing against the joist etc. can all cause floor squeaks but are not related to the joist itself.  Refer to page 8 of the TJI® Specifiers Guide and the Weyerhaeuser Technical Resource Sheet Prevention and Repair of Floor System Squeaks for more information.