The physical void between parallel framing joists in a floor or ceiling structure. This space is heavily utilized by other trades to route plumbing, ductwork, and electrical runs. Carpenters must often install solid blocking or bridging within the interjoist to prevent the framing members from twisting under a heavy load.
Heard on the job
We've to run the HVAC ducting right down the center of the interjoist before putting the subfloor down.
Insider tip
Always check the interjoist for existing plumbing or wiring before driving long screws through the subfloor.
Also heard as
- joist bay
- joist cavity